Jones v Commonwealth

[2023] HCA 34

HIGH COURT OF AUSTRALIA

KIEFEL CJ,
GAGELER, GORDON, EDELMAN, STEWARD, GLEESON AND JAGOT JJ

PHYLLIP JOHN JONES  PLAINTIFF

AND

COMMONWEALTH OF AUSTRALIA & ORS  DEFENDANTS

Jones v Commonwealth of Australia

[2023] HCA 34

Date of Hearing: 15 June 2023

Date of Judgment: 1 November 2023

B47/2022

ORDER

The questions stated for the opinion of the Full Court in the special case filed on 4 April 2023 be answered as follows:

Question 1: Is s 34(2)(b)(ii) of the Australian Citizenship Act 2007 (Cth) invalid in its operation in respect of the plaintiff because:

(a)it is not supported by s 51(xix) of the Constitution; or

(b)it reposes in the Minister the exclusively judicial function of punishing criminal guilt?

Answer:        No.

Question 2:What, if any, relief should be granted to the plaintiff?

Answer:None.

Question 3:Who should pay the costs of the special case?

Answer:The plaintiff.

Representation

S H Hartford Davis with D J Reynolds, S J Hoare and K E W Bones for the plaintiff (instructed by Fisher Dore Lawyers)

S P Donaghue KC, Solicitor-General of the Commonwealth, and F I Gordon SC with L G Moretti and A N Regan for the defendants (instructed by Australian Government Solicitor)

Notice:  This copy of the Court's Reasons for Judgment is subject to formal revision prior to publication in the Commonwealth Law Reports.

CATCHWORDS

Jones v Commonwealth of Australia

Constitutional law (Cth) – Powers of Commonwealth Parliament – Power to make laws with respect to naturalisation and aliens – Cessation of Australian citizenship – Where s 34(2)(b)(ii) of Australian Citizenship Act 2007 (Cth) ("Act"), in context, provided Minister may revoke person's Australian citizenship acquired by conferral if, among other matters, person "convicted of a serious offence" within meaning of s 34(5) after making application to become Australian citizen – Where s 34(5) provided person "convicted of a serious offence" for purposes of s 34 if person convicted of offence against Australian law or foreign law for which person sentenced to death or to "serious prison sentence" and person committed offence before becoming Australian citizen – Where s 3 defined "serious prison sentence" as sentence of imprisonment for period of at least 12 months – Where plaintiff British and Australian citizen – Where plaintiff Australian citizen by virtue of certificate of Australian citizenship – Where plaintiff convicted of criminal offences relating to conduct before becoming Australian citizen and sentenced to more than 12 months' imprisonment – Where Minister revoked plaintiff's Australian citizenship under s 34(2) of Act – Whether s 34(2)(b)(ii) of Act supported by s 51(xix) of Constitution – Whether s 34(2)(b)(ii) law with respect to naturalisation.

Constitutional law (Cth) – Judicial power of Commonwealth – Cessation of Australian citizenship – Where precondition to Minister's power to revoke person's Australian citizenship under s 34(2)(b)(ii) of Act was, among other things, that person convicted of and sentenced to imprisonment for period of at least 12 months for offence committed before becoming Australian citizen – Whether s 34(2)(b)(ii) contrary to Ch III of Constitution for conferring upon Minister exclusively judicial function of punishing criminal guilt – Whether s 34(2)(b)(ii) limited to what is reasonably capable of being seen as necessary for purpose of protecting integrity of naturalisation process.

Words and phrases – "alien", "cessation of citizenship", "citizen", "citizenship", "denationalisation", "denaturalisation", "deprivation of citizenship", "good character", "integrity of naturalisation process", "legitimate non-punitive purpose", "naturalisation", "naturalization", "people of the Commonwealth", "proportionality", "public interest", "punishing criminal guilt", "punishment", "punitive", "reasonable necessity", "revocation of citizenship", "statutory precondition".

Constitution, s 51(xix), Ch III.

Australian Citizenship Act 2007 (Cth), s 34.

1. KIEFEL CJ, GAGELER, GLEESON AND JAGOT JJ.   Subject to the Constitution, including the constraint imposed by Ch III that any legislative vesting of judicial power can be only in a court, s 51(xix) of the Constitution confers power on the Commonwealth Parliament to make laws with respect to "naturalization and aliens". Questions concerning the scope and application of the "aliens" limb of s 51(xix) have been considered and determined in numerous prior decisions. The questions in this special case, in contrast, can be determined solely by reference to the "naturalization" limb.

2. The proceeding in the original jurisdiction of the High Court which gives rise to the special case involves a challenge to the validity of s 34(2)(b)(ii) of the Australian Citizenship Act 2007 (Cth) ("the Citizenship Act") in its application to a person who is a national or citizen of another country and who became an Australian citizen by virtue of the grant of a certificate of Australian citizenship under Div 2 of Pt III of the now repealed Australian Citizenship Act 1948 (Cth) ("the 1948 Act"). The challenged provision, as will be seen, operates to empower a Minister administering the Citizenship Act to revoke the Australian citizenship of such a person if the person is convicted of and sentenced to imprisonment for a period of at least 12 months for an offence committed before the person became an Australian citizen and if the Minister is satisfied that it would be contrary to the public interest for the person to remain an Australian citizen.

3. The substantive question raised in the special case is whether the challenged provision is invalid in its application to such a person either because it is not supported by s 51(xix) of the Constitution or because it reposes in the Minister the exclusively judicial function of punishing criminal guilt contrary to Ch III of the Constitution.

4. The short answer is that the provision is valid. It provides for "an act or process of denaturalization"[1] which is supported by the "naturalization" limb of s 51(xix) of the Constitution. The power it confers on the Minister to denaturalise an Australian citizen is not a power to punish criminal guilt and is not otherwise exclusively judicial. The Commonwealth Parliament's choice to confer that power on the Minister rather than a court therefore is not contrary to Ch III of the Constitution.

   [1]See Nolan v Minister for Immigration and Ethnic Affairs (1988) 165 CLR 178 at 183; Alexander v Minister for Home Affairs (2022) 96 ALJR 560 at 573 [36]; 401 ALR 438 at 447.

   The circumstances of the plaintiff

5. The plaintiff, Mr Jones, was born in 1950 in the United Kingdom. Under the law of the United Kingdom, he became a citizen of the United Kingdom and its Colonies at birth and a British citizen in 1981. He remains a British citizen.

6. Mr Jones migrated to Australia with his parents in 1966. In 1988, he applied for and was granted a certificate of Australian citizenship under s 13(1) of the 1948 Act. He afterwards took an oath or made a declaration of allegiance in the manner provided by s 15(2) in accordance with the appropriate form set out in Sch 2 to the 1948 Act. He thereupon became an Australian citizen by operation of s 15(1) of the 1948 Act.

7. In 2003, Mr Jones was convicted in the District Court of Queensland of five counts of indecent dealing and indecent assault committed at various times between 1980 and 2001. Two of those five counts related to conduct that occurred entirely before he became an Australian citizen in 1988. For each of those five counts, he was sentenced to a term of imprisonment of two and a half years to be served concurrently with each other term.

8. In 2018, the then Minister for Home Affairs, Immigration and Border Protection revoked Mr Jones' Australian citizenship under s 34(2) of the Citizenship Act. By that time, Mr Jones had been an Australian citizen for 29 years and had lived in Australia continuously for 52 years. Since arriving in 1966, he had left Australia only twice, for a combined total of around 27 days. On both occasions, he had travelled on vacation on an Australian passport.

9. The result of the action of the Minister was that Mr Jones immediately ceased to be an Australian citizen by operation of s 34(4) of the Citizenship Act. By operation of s 35(3) of the Migration Act 1958 (Cth) ("the Migration Act"), he was immediately taken to have been granted an ex-citizen visa.

10. In 2021, the Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs cancelled Mr Jones' ex-citizen visa under s 501(2) of the Migration Act. In 2022, Mr Jones was taken into immigration detention under s 189 of the Migration Act. He has remained in immigration detention since then.

    The applicable legislative provisions, their legislative history and their legislative purpose

11. When Mr Jones applied for and was granted his certificate of Australian citizenship in 1988, Div 2 of Pt III of the 1948 Act was headed "Grant of Australian Citizenship". Division 4 of the same Part was headed "Loss of Citizenship". Both of those Divisions had been substantially amended by the Australian Citizenship Amendment Act 1984 (Cth) ("the 1984 Amendment Act").

12. Within Div 2 of Pt III of the 1948 Act, s 13 provided for the grant of a certificate of Australian citizenship and s 15 provided for the effect of such a grant. Section 13(1) provided that "the Minister may, in his discretion, upon application ... grant a certificate of Australian citizenship to a person who satisfies the Minister" that, amongst other things, "he is of good character"[2]. Section 15(1) provided that a person to whom a certificate of Australian citizenship was granted under the Division who took an oath or made an affirmation of allegiance, in the manner provided by s 15(2) and in accordance with the appropriate form set out in Sch 2, thereupon became an Australian citizen.

    [2]Section 13(1)(f) of the 1948 Act.

13. The precondition to the grant of a certificate of Australian citizenship under s 13(1) of the 1948 Act that the Minister be satisfied that the person was of "good character" required the Minister to be satisfied of the person's "enduring moral qualities", being their "disposition rather than general reputation"[3]. Past conviction of a serious offence was relevant to the requisite ministerial assessment of character, without necessarily being determinative of that assessment[4]. That was because the conviction amounted to conclusive evidence of the past criminal conduct to which it related[5].

    [3]Minister for Immigration and Multicultural Affairs v Jia Legeng (2001) 205 CLR 507 at 529 [65].

    [4]Minister for Immigration and Multicultural Affairs v Jia Legeng (2001) 205 CLR 507 at 529-530 [65].

    [5]Rogers v The Queen (1994) 181 CLR 251 at 284-285. Compare Minister for Immigration and Multicultural Affairs v SRT (1999) 91 FCR 234 at 244-245 [44]-[46].

14. Within Div 4 of Pt III of the 1948 Act was s 21. It was headed "Deprivation of citizenship". Section 21(1) provided:

    "Where —

    (a)a person who is an Australian citizen by virtue of a certificate of Australian citizenship —

    (i)has been convicted of an offence against section 50 in relation to the application for his certificate of Australian citizenship; or

    (ii)has, at any time after furnishing the application for his certificate of Australian citizenship (including a time after the grant of the certificate), been convicted of an offence against a law in force in a foreign country or against a law of the Commonwealth, a State or Territory for which he has been sentenced to death or to imprisonment for life or for a period of not less than 12 months, being an offence committed at any time before the grant of the certificate (including a time before the furnishing of the application); and

    (b)the Minister is satisfied that it would be contrary to the public interest for the person to continue to be an Australian citizen,

    the Minister may, in his discretion, by order, deprive the person of his Australian citizenship, and the person shall, upon the making of the order, cease to be an Australian citizen."

15. Section 50 of the 1948 Act, to which reference was made in s 21(1)(a)(i), made it an offence to make a knowingly false or misleading representation or statement, or to conceal or cause to be concealed a material circumstance, for a purpose of or in relation to the 1948 Act.

16. Earlier forms of s 21(1)(a)(i) and s 50 had been inserted into the 1948 Act in 1958[6]. However, s 21(1) in the form which included s 21(1)(a)(ii) had been inserted only by the 1984 Amendment Act[7]. Prior to the 1984 Amendment Act, the introduction of a provision along the lines of s 21(1)(a)(ii) had been foreshadowed in a Ministerial Statement to the House of Representatives in 1982.

    [6]See ss 7 and 11 of the Nationality and Citizenship Act 1958 (Cth).

    [7]See s 15 of the 1984 Amendment Act.

17. In the Ministerial Statement to the House of Representatives in 1982, the Minister for Immigration and Ethnic Affairs, Mr Macphee, stressed the importance of good character to the grant of Australian citizenship and the relevance of a criminal record to the assessment of good character[8]. He foreshadowed s 21(1)(a)(ii) in going on to say that there was "a case ... for depriving a person of citizenship if he or she has committed a serious offence before the grant of citizenship even though the conviction occurs after the grant"[9]. He explained[10]:

    "Deprivation of Australian citizenship under such a proposed amendment would not constitute an additional penalty to that imposed by a court on the conviction of the person concerned. The deprivation powers should be invoked only if an applicant has obtained citizenship by false pretences; in other words, where he has obtained something he was not entitled to. Deprivation is not automatic under any circumstances. The Minister must consider the full facts of the case and be satisfied that it would be in the public interest to deprive a person of citizenship before he orders deprivation."

    [8]Australia, House of Representatives, Parliamentary Debates (Hansard), 6 May 1982 at 2359.

    [9]Australia, House of Representatives, Parliamentary Debates (Hansard), 6 May 1982 at 2361.

    [10]Australia, House of Representatives, Parliamentary Debates (Hansard), 6 May 1982 at 2361.

18. The policy intent revealed by the Ministerial Statement in 1982 was elaborated on the following year by a successor of Mr Macphee in the office of Minister for Immigration and Ethnic Affairs, Mr West, in his second reading speech for the Bill which became the 1984 Amendment Act. With implicit reference to s 21(1)(a)(i), Mr West said that "[i]n the case of a person obtaining Australian citizenship by fraud, deceit, the concealment of information or any other dishonest means, the Minister will have discretion to deprive that person of citizenship"[11]. With implicit reference to s 21(1)(a)(ii), he added:

    "This discretion also extends to a person convicted of a major offence committed, but not known about, before that grant of citizenship. I stress that deprivation of Australian citizenship could only occur for offences committed before the grant of citizenship. Moreover, it will occur only if the responsible Minister, after careful consideration of all the facts, is satisfied that it is in the public interest for a person not to remain an Australian citizen. The law will not allow a person to be deprived of citizenship if it has been obtained properly and honestly."

    [11]Australia, House of Representatives, Parliamentary Debates (Hansard), 7 December 1983 at 3369.

19. The purpose of s 21(1)(a)(ii) of the 1948 Act – the "public interest sought to be protected and enhanced"[12] by that provision – was accordingly revealed by the Ministerial Statement and the second reading speech not to be the imposition of punishment in addition to that imposed by a court on the conviction of the person concerned. The purpose of s 21(1)(a)(ii) was rather aligned with the purpose of s 21(1)(a)(i). The purpose of both was to safeguard the integrity of the administrative function by which ministerial satisfaction that the person was of good character was a prerequisite to the person being granted Australian citizenship and in respect of which conviction of a serious offence would have been relevant to the performance of that function.

    [12]Alexander v Minister for Home Affairs (2022) 96 ALJR 560 at 584 [102]; 401 ALR 438 at 462, quoting Cunliffe v The Commonwealth (1994) 182 CLR 272 at 300. See also Falzon v Minister for Immigration and Border Protection (2018) 262 CLR 333 at 341 [20], quoting Re Woolley; Ex parte Applicants M276/2003 (2004) 225 CLR 1 at 26 [60].

20. This means s 21(1)(a)(ii) operated to ensure that quirks of timing in the commencement and conclusion of criminal proceedings did not allow a person's prior criminal conduct to remain unconsidered in the ministerial determination of whether the person was of the requisite character to be granted Australian citizenship. In so doing, the provision would also create a disincentive for an applicant for Australian citizenship to conceal prior criminal conduct during the application process.

21. The "public interest", which the Minister was required to consider under s 21(1)(b) of the 1948 Act before depriving a person of Australian citizenship where s 21(1)(a)(ii) was engaged, "classically import[ed] a discretionary value judgment to be made by reference to undefined factual matters, confined only 'in so far as the subject matter and the scope and purpose of the statutory enactments may enable ... given reasons to be [pronounced] definitely extraneous to any objects the legislature could have had in view'"[13]. Section 21(1)(b) permitted the Minister to consider whether the Minister would have been satisfied that the person was of good character had the Minister known at the time of the grant of citizenship of the offence or offences in respect of which the person was later convicted and sentenced. But, of course, s 21(1)(b) did not limit the Minister to that consideration. It permitted the Minister also to consider, amongst other things, whether the person might have been rehabilitated in the interim.

    [13]O'Sullivan v Farrer (1989) 168 CLR 210 at 216, quoting Water Conservation and Irrigation Commission (NSW) v Browning (1947) 74 CLR 492 at 505.

22. The 1948 Act was repealed upon the commencement of the Citizenship Act by the Australian Citizenship (Transitionals and Consequentials) Act 2007 (Cth) ("the Consequential Provisions Act")[14]. On and from its commencement, the Citizenship Act included as an Australian citizen a person who was an Australian citizen under the 1948 Act immediately before that commencement and who had not ceased to be an Australian citizen under the Citizenship Act[15]. Mr Jones was within that category.

    [14]See ss 2, 3 and item 42 of Sch 1 to the Consequential Provisions Act.

    [15]Section 4(1)(b) of the Citizenship Act.

23. Subdivision B of Div 2 of Pt 2 of the Citizenship Act, headed "Citizenship by conferral", deals with a topic which corresponds broadly to the topic of the grant of Australian citizenship previously dealt with in Div 2 of Pt III of the 1948 Act. The scheme of Subdiv B is to provide for a person to acquire Australian citizenship in consequence of a ministerial approval of an application for Australian citizenship. Corresponding to the precondition to the grant of a certificate of Australian citizenship under s 13(1) of the 1948 Act that the Minister was satisfied that the person who had applied for the certificate was of "good character", a standard precondition to the Minister approving a person becoming an Australian citizen under Subdiv B is that the Minister is satisfied that the person "is of good character at the time of the Minister's decision on the application"[16].

    [16]See s 24(1A) read with s 21(2)(h), (3)(f), (4)(f), (6)(d) and (7)(d) of the Citizenship Act.

1. By operation of a provision of the Consequential Provisions Act, a person in the position of Mr Jones, who had been an Australian citizen under Div 2 of Pt III of the 1948 Act, was "taken ... to be" an Australian citizen under Subdiv B of Div 2 of Pt 2 on the commencement of the Citizenship Act[17].

   [17]See s 3 and item 2(2) of Pt 1 of Sch 3 to the Consequential Provisions Act.

2. Division 3 of Pt 2 of the Citizenship Act, headed "Cessation of Australian citizenship", deals with a topic which corresponds broadly to the topic of the loss of Australian citizenship previously dealt with in Div 4 of Pt III of the 1948 Act. Within Div 3 is s 34, headed "Revocation by Minister – offences or fraud". The effect of s 34 is explained in the simplified outline of the Division to be that "if you did not automatically become an Australian citizen, the Minister can revoke your citizenship in circumstances involving offences or fraud"[18].

   [18]Section 32A of the Citizenship Act.

3. Section 34(2)(b)(i) and (ii) of the Citizenship Act correspond to s 21(1)(a)(i) and (ii) of the 1948 Act. Section 34(2)(b)(i) and (ii) in context provide:

   "The Minister may, by writing, revoke a person's Australian citizenship if:

   (a)the person is an Australian citizen under Subdivision B of Division 2 ...; and

   (b)       any of the following apply:

   (i)the person has been convicted of an offence against section 50 of this Act ... in relation to the person's application to become an Australian citizen;

   (ii)the person has, at any time after making the application to become an Australian citizen, been convicted of a serious offence within the meaning of subsection (5);

   ...; and

   (c)the Minister is satisfied that it would be contrary to the public interest for the person to remain an Australian citizen."

4. Section 34(3) adds:

   "However, the Minister must not decide under subsection (2) to revoke a person's Australian citizenship if:

   (a)the Minister may revoke the person's Australian citizenship under that subsection only because of the application of subparagraph (2)(b)(ii); and

   (b)the Minister is satisfied that the person would, if the Minister were to revoke the person's Australian citizenship, become a person who is not a national or citizen of any country."

5. Section 34(4) provides for the consequence of a ministerial decision under s 34(2). The consequence is that "[i]f the Minister revokes a person's Australian citizenship, the person ceases to be an Australian citizen at the time of the revocation".

6. Section 34(5), to which reference is made in s 34(2)(b)(ii), provides:

   "For the purposes of this section, a person has been convicted of a serious offence if:

   (a)the person has been convicted of an offence against an Australian law or a foreign law, for which the person has been sentenced to death or to a serious prison sentence; and

   (b)the person committed the offence at any time before the person became an Australian citizen."

7. The expression "serious prison sentence", used in s 34(5)(a), is defined to mean a sentence of imprisonment for a period of at least 12 months[19].  

   [19]Section 3 of the Citizenship Act.

8. Section 50, to which reference is made in s 34(2)(b)(i), corresponds to s 50 of the 1948 Act in making it an offence to make a knowingly false or misleading representation or statement, or to conceal or cause or permit to be concealed a material circumstance, for a purpose of or in relation to the Citizenship Act.

9. In their application to a person who, like Mr Jones, had been an Australian citizen under Div 2 of Pt III of the 1948 Act and who was taken from the commencement of the Citizenship Act to be an Australian citizen under Subdiv B of Div 2 of Pt 2 of the Citizenship Act, s 34(2)(b)(i) and (ii) are given a modified operation by the Consequential Provisions Act[20]. Section 34(2)(b)(i) applies to such a person "as if" it also referred to the person's conviction, at any time, of an offence against s 50 of the 1948 Act in relation to the person's application for the certificate of Australian citizenship under that Act[21]. Section 34(2)(b)(ii) applies to such a person "as if" it also referred to the person's conviction, at any time after the person made the application for the certificate of Australian citizenship under the 1948 Act, of an offence referred to in s 21(1)(a)(ii) of the 1948 Act that the person committed at any time before the grant of the certificate[22].

   [20]See s 3 and item 6(1) of Pt 1 of Sch 3 to the Consequential Provisions Act.

   [21]See s 3 and item 6(2) of Pt 1 of Sch 3 to the Consequential Provisions Act.

   [22]See s 3 and item 6(3) of Pt 1 of Sch 3 to the Consequential Provisions Act.

10. Thus, in their modified application to a person in the position of Mr Jones, s 34(2)(a), (b)(ii) and (c) of the Citizenship Act replicate the power which the Minister administering the 1948 Act had under s 21(1)(a)(ii) and (b) of that Act at the time Mr Jones was granted his certificate of Australian citizenship under s 13(1) of that Act enabling him to become an Australian citizen by operation of s 15(1) of that Act. The power which the Minister administering the 1948 Act then had, and which the Minister administering the Citizenship Act has retained, was and has at all times remained a power administratively to revoke the Australian citizenship administratively granted to the person. The power was and has remained exercisable if: (1) at any time after the person applied for their certificate of Australian citizenship, the person was convicted of and sentenced to imprisonment for a period of at least 12 months for an offence committed before the person became an Australian citizen; and (2) the Minister was satisfied that it would be contrary to the public interest for the person to remain an Australian citizen.

11. Plainly enough, the purpose of s 34(2)(a), (b)(ii) and (c) of the Citizenship Act in that modified application remains the purpose of s 21(1)(a)(ii) and (b) of the 1948 Act at the time Mr Jones was granted his certificate of Australian citizenship. The purpose of s 34(2)(a), (b)(ii) and (c) in that modified application is to continue to protect the integrity of the administrative process by which that and other grants were made under s 13(1) of the 1948 Act.

12. The consequence of that legislative continuity has been that, at the time he became an Australian citizen in 1988 by force of s 15(1) of the 1948 Act and at all times thereafter, Mr Jones was and remained at risk of revocation of his Australian citizenship by a responsible Minister if Mr Jones was convicted of and sentenced to imprisonment for a period of at least 12 months for an offence committed before he became an Australian citizen and the Minister was satisfied that it would be contrary to the public interest for Mr Jones to remain an Australian citizen. It was Mr Jones' conviction and sentence in 2003 for offences committed between 1980 and 1988 which led to that risk materialising in 2018.

    A narrow path to validity

13. The hearing of the special case occurred immediately after the hearing in Benbrika v Minister for Home Affairs[23]. In the course of that hearing, it became apparent that the issues needing to be resolved to answer the substantive question asked in the special case in this matter are quite narrow.

    [23][2023] HCA 33.

14. In respect of the first part of the substantive question, which asks whether s 34(2)(b)(ii) of the Citizenship Act is invalid in its application to Mr Jones on the basis that it is not supported by s 51(xix) of the Constitution, the Solicitor-General of the Commonwealth relied on reasoning in Alexander v Minister for Home Affairs[24] and Re Minister for Immigration and Multicultural Affairs; Ex parte Te[25] and on the decision in Meyer v Poynton[26] to argue that s 51(xix) empowers the Commonwealth Parliament to subject the grant of Australian citizenship to an alien through a process of naturalisation to any condition the Parliament might see fit to impose. However, the Solicitor-General accepted that it was sufficient for the purpose of supporting s 34(2)(b)(ii) to confine the argument to a condition the purpose of which is to protect the integrity of the naturalisation process itself.

    [24](2022) 96 ALJR 560 at 573-574 [36]-[38]; 401 ALR 438 at 447-448.

    [25](2002) 212 CLR 162 at 171-173 [24]-[31].

    [26](1920) 27 CLR 436 at 441.

15. Counsel for Mr Jones argued that the reasoning in Alexander and Te should be confined, and that Meyer should be distinguished or overruled. They argued that the naturalisation limb of s 51(xix) of the Constitution should be construed to exclude power on the part of the Commonwealth Parliament to make Australian citizenship subject to an ongoing condition that is "unreasonable" or that remains applicable once the citizen who was formerly an alien has become "integrated and absorbed into the political community". However, they ultimately accepted that s 34(2)(b)(ii) of the Citizenship Act would not overreach either of the limitations for which they argued if it meets the criterion, which both parties accepted it must in any event meet to comply with Ch III of the Constitution, that it is reasonably capable of being seen as necessary for the purpose of protecting the integrity of the naturalisation process.

16. In respect of the second part of the substantive question, which asks whether s 34(2)(b)(ii) of the Citizenship Act is invalid in its application to Mr Jones on the basis that it reposes in the Minister the exclusively judicial function of punishing criminal guilt contrary to Ch III of the Constitution, the arguments of both parties took as their starting point the holding in Alexander (now confirmed in Benbrika) that the principle in Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs[27] applies to a Commonwealth law empowering the Commonwealth Executive to strip a person of Australian citizenship in the same way as it applies to a Commonwealth law empowering the Commonwealth Executive to detain a person in custody. Both parties accepted the principle in Lim to result in such a law being characterised as "punitive", and therefore as contrary to Ch III, unless the law is reasonably capable of being seen as necessary for a legitimate non-punitive purpose[28].

    [27](1992) 176 CLR 1.

    [28]Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs (1992) 176 CLR 1 at 33; Kruger v The Commonwealth (1997) 190 CLR 1 at 162; Falzon v Minister for Immigration and Border Protection (2018) 262 CLR 333 at 343-344 [27]-[29]; Alexander v Minister for Home Affairs (2022) 96 ALJR 560 at 584-585 [106]; 401 ALR 438 at 463.

17. Consistently with the legislative context and history to which reference has been made, Ms Gordon KC, who appeared with the Solicitor-General, identified the legitimate non-punitive purpose of s 34(2)(b)(ii) of the Citizenship Act to be the protection of the integrity of the naturalisation process. Counsel for Mr Jones did not dispute the characterisation of that purpose as legitimate and non-punitive. They argued, rather, that s 34(2)(b)(ii) is not reasonably capable of being seen as necessary for that purpose.

18. The answers to both parts of the substantive question reserved were by those means revealed in the course of the hearing to turn on a single dispositive issue: whether s 34(2)(b)(ii) of the Citizenship Act is reasonably capable of being seen as necessary to protect the integrity of the naturalisation process in accordance with which Mr Jones was granted his certificate of Australian citizenship under s 13(1) of the 1948 Act so as to have become an Australian citizen under s 15(1) of that Act.

    The test of reasonable necessity

19. The word "necessary", Gleeson CJ pointed out in Mulholland v Australian Electoral Commission[29], "does not always mean 'essential' or 'unavoidable', especially in a context where a court is evaluating a decision made by someone else who has the primary responsibility for setting policy". "There is, in Australia", his Honour noted, "a long history of judicial and legislative use of the term 'necessary', not as meaning essential or indispensable, but as meaning reasonably appropriate and adapted"[30]. That was the sense in which the word was used in the formulation of the principle in Lim.

    [29](2004) 220 CLR 181 at 199 [39].

    [30](2004) 220 CLR 181 at 199-200 [39].

20. In Falzon v Minister for Immigration and Border Protection[31], Kiefel CJ, Bell, Keane and Edelman JJ rejected an argument that the criterion of reasonable necessity in the application of the principle in Lim is to be assessed by means of the analytical tool of structured proportionality which has been adopted by a majority of this Court in the context of considering infringement of the implied constitutional freedom of political communication and the express guarantee of freedom of interstate trade and commerce in s 92 of the Constitution. Their Honours emphasised that use of that analytical tool is inappropriate to the application of the principle in Lim because the purpose and framework of the analysis is different. In the context of the implied constitutional freedom of political communication and the express guarantee of freedom of interstate trade and commerce, the analysis is ultimately directed to a second-stage question of justification: whether a burden found at the first stage of analysis to be imposed by a law on a constitutionally guaranteed freedom is nonetheless justified in its nature and extent. In the application of the principle in Lim, the criterion of reasonable necessity can be described as requiring a law which empowers the imposition of a form of detriment to be justified[32]. But the application of the principle in Lim is ultimately directed to a single question of characterisation: whether the power to impose the detriment conferred by the law is properly characterised as punitive and therefore as exclusively judicial.

    [31](2018) 262 CLR 333 at 343-344 [25]-[32].

    [32](2018) 262 CLR 333 at 344 [33]. See also North Australian Aboriginal Justice Agency Ltd v Northern Territory (2015) 256 CLR 569 at 611-612 [98].

21. Judicial determination of whether a law is reasonably capable of being seen as necessary for a legitimate non-punitive purpose in the application of the principle in Lim must proceed in a manner that is both faithful to the constitutional values safeguarded by that principle, as explained in Lim[33] and now reinforced in Benbrika[34], and mindful of the procedural and substantive limitations inherent in the performance of the judicial function. It would fit uncomfortably with the judicial tradition of which the emergence of the principle in Lim is part to attempt to constrain the analytical techniques or to map out subsidiary principles in the abstract.

    [33](1992) 176 CLR 1 at 27-28.

    [34][2023] HCA 33 at [36]-[39].

22. As with other questions pertaining to judicial power, historical practices and classifications are informative. And as with any constitutional question, looking to how comparable laws have in practice been seen by courts discharging comparable constitutional or quasi-constitutional responsibilities in comparable jurisdictions can be instructive.

    Application of the test

23. Reference was made in Alexander[35] to Trop v Dulles[36]. There a statute providing for naval and military personnel to lose their citizenship upon conviction by court martial of wartime desertion was held to be "penal" and to infringe the guarantee against "cruel and unusual punishment" in the Eighth Amendment to the Constitution of the United States. Warren CJ contrasted that punitive form of "denationalization" with forms of "denaturalization" the constitutionality of which had been upheld in earlier cases[37]. The Chief Justice said[38]:

    "Denaturalization is not imposed to penalize the alien for having falsified his application for citizenship; if it were, it would be a punishment. Rather, it is imposed in the exercise of the power to make rules for the naturalization of aliens. In short, the fact that deportation and denaturalization for fraudulent procurement of citizenship may be imposed for purposes other than punishment affords no basis for saying that in this case denationalization is not a punishment."

    [35](2022) 96 ALJR 560 at 598 [172], 599 [174], 613 [248], 629 [325]-[326], 632 [337]; 401 ALR 438 at 480, 481, 500, 521-522, 525.

    [36](1958) 356 US 86.

    [37]Schneiderman v United States (1943) 320 US 118; Baumgartner v United States (1944) 322 US 665.

    [38](1958) 356 US 86 at 98-99 (footnote omitted).

24. Understood in the context of the earlier cases to which he referred, the reference by Warren CJ to "denaturalization for fraudulent procurement of citizenship" was not confined to cases of fraud or concealment but encompassed denaturalisation for citizenship proven to have been "illegally procured", including where a finding made at the time of grant of citizenship that a statutory precondition to the grant had been met was subsequently proven by additional "clear, unequivocal, and convincing" evidence to have been erroneous when made[39].

    [39]Schneiderman v United States (1943) 320 US 118 at 124-125; Baumgartner v United States (1944) 322 US 665 at 675, 678. See also Fedorenko v United States (1981) 449 US 490 at 506-507.

25. More recent examples of courts in the United States holding denaturalisation in cases of "illegally procured" citizenship to be non-punitive, consistently with Trop, have included cases in which findings made at the time of the grant of citizenship that a statutory precondition that the applicant "is a person of good moral character" was met have subsequently been proven erroneous by reference to evidence which has constituted or included later convictions relating to prior criminal conduct[40].

    [40]eg United States v Nunez-Garcia (2003) 262 F Supp 2d 1073; United States v Bogacki (2012) 925 F Supp 2d 1288; United States v Vilchis Rojas (ND Ill, No 19-cv-8034, 5 May 2021).

26. For the purpose of determining whether a Commonwealth law providing for denaturalisation is reasonably capable of being seen as necessary for the legitimate non-punitive purpose of protecting the integrity of the naturalisation process so as to escape characterisation as punishment, what is usefully taken from that body of case law in the United States is the significance of relating the provision for denaturalisation to one or more of the statutory prerequisites to naturalisation.

27. The form of denaturalisation for which s 34(2)(b)(ii) combines with s 34(2)(a) and (c) of the Citizenship Act to provide, in their modified application to a person in the position of Mr Jones, is reasonably capable of being seen as necessary to protect the integrity of the naturalisation process for which ss 13(1) and 15(1) of the 1948 Act provided. That is so when attention is focused on four features of the legislative context and history earlier recounted.

28. The first of those features is the statutory precondition to the grant of a certificate of Australian citizenship under s 13(1) of the 1948 Act that the Minister administering the 1948 Act was satisfied that the person was of "good character". The second feature is that prior serious offending was relevant to the assessment which the Minister needed to undertake to determine whether that precondition was met. The third is that any later conviction of a prior serious offence was likely to call into question the correctness and completeness of the evidentiary basis on which the ministerial assessment was made. The fourth feature is that s 34(2)(b)(ii) replicates, and in so doing perpetuates, the substance of the regime for the revocation of citizenship upon later conviction of a past serious offence which existed under s 21(1)(a)(ii) of the 1948 Act on and from the moment citizenship was conferred under s 15(1) of that Act. The inclusion of s 34(2)(b)(ii) accordingly subjected a person in the position of Mr Jones to no greater jeopardy of denaturalisation than the person faced, and which the person must be taken to have known that the person would face, when applying for and obtaining Australian citizenship under the 1948 Act. The effect of s 34(2)(b)(ii), like s 21(1)(a)(ii) of the 1948 Act before it, was to permit what had been considered and done administratively to be reconsidered and undone administratively if at any time later a criminal conviction were to demonstrate the original decision to have been made on materially incorrect or incomplete information.

1. Those four features in combination answer the principal criticism of s 34(2)(b)(ii) made by counsel for Mr Jones in support of their argument that the provision goes further than is reasonably capable of being seen as necessary for the acknowledged protective purpose because "it lacks criteria directly to connect the citizen's offending to some irregularity in the process of naturalization". The connection of s 34(2)(b)(ii) to irregularity in the process of naturalisation which resulted in Mr Jones acquiring Australian citizenship in 1988 is substantial and is unbroken.

2. Of the other criticisms made by counsel for Mr Jones in support of their argument that s 34(2)(b)(ii) goes further than is reasonably capable of being seen as necessary for the acknowledged protective purpose, three warrant specific responses. The first was that the requirement of s 34(2)(c) that the Minister be satisfied that it would be contrary to the public interest for the person whose citizenship is revoked to remain an Australian citizen "is overbroad" and would permit the Minister to use the power of revocation of citizenship "for punitive purposes". The second was the absence of a time limit for the exercise of the power to revoke citizenship after the date of conviction. The third was what was said to be a discrepancy created by the limitation on the power of revocation imposed by s 34(3) applying to revocation of citizenship in circumstances covered by s 34(2)(b)(ii) but not applying to revocation of citizenship in circumstances covered by s 34(2)(b)(i).

3. The requirement of s 34(2)(c) that the Minister be satisfied that it would be contrary to the public interest for the person whose citizenship is revoked to remain an Australian citizen furthers the purpose of protecting the integrity of the naturalisation process for which ss 13(1) and 15(1) of the 1948 Act provided by facilitating reconsideration of the critical question whether the person was of good character at the time of grant without constraining the capacity of the Minister to have regard to subsequent rehabilitation and integration into the Australian community. Were the Minister to purport to invoke the power of revocation of the Australian citizenship of someone convicted of a serious crime for the purposes of retribution, denunciation or deterrence under the guise of being satisfied that it would be contrary to the public interest for that person to remain an Australian citizen, the purported exercise of power would be unauthorised on the basis that the power would have been exercised for an extraneous and improper purpose[41].

   [41]Water Conservation and Irrigation Commission (NSW) v Browning (1947) 74 CLR 492 at 505. Compare Re Sergi and Minister for Immigration and Ethnic Affairs (1979) 2 ALD 224 at 230-231.

4. Once it is understood that s 34(2) would not authorise the Minister to revoke the Australian citizenship of someone convicted of a serious crime for a purpose of retribution, denunciation or deterrence, the absence of a time limit within which the Minister is required to exercise the power after the date of conviction cannot detract from the non-punitive character of s 34(2)(b)(ii) established by the combination of features to which reference has been made.

5. The reason why s 34(3), prohibiting revocation of the Australian citizenship of a person who the Minister is satisfied would thereby not be a national or citizen of any country, applies to revocation of citizenship in circumstances covered by s 34(2)(b)(ii) but not in circumstances covered by s 34(2)(b)(i) lies in the Convention on the Reduction of Statelessness[42]. An obligation of Australia under that Convention is that it "not deprive a person of its nationality if such deprivation would render [the person] stateless"[43]. The obligation is subject to an exception "where the nationality has been obtained by misrepresentation or fraud"[44]. The application of s 34(3) in circumstances covered by s 34(2)(b)(ii) gives effect to the obligation; the non-application of s 34(3) in circumstances covered by s 34(2)(b)(i) reflects the limited scope of the exception.

   [42][1975] ATS 46.

   [43]Article 8(1).

   [44]Article 8(2)(b).

   Formal answers to questions

6. The questions stated by the parties in the special case and the answers to them are as follows:

   (1)Is s 34(2)(b)(ii) of the Citizenship Act invalid in its operation in respect of the plaintiff because:

   (a)it is not supported by s 51(xix) of the Constitution; or

   (b)it reposes in the Minister the exclusively judicial function of punishing criminal guilt?

   Answer:         No.

   (2)       What, if any, relief should be granted to the plaintiff?

   Answer:         None.

   (3)       Who should pay the costs of the special case?

   Answer:         The plaintiff.

7. GORDON J. The plaintiff became an Australian citizen in 1988 by a grant of Australian citizenship under Div 2 of Pt III of the now repealed Australian Citizenship Act 1948 (Cth) ("the 1948 Act"). In May 2003, the plaintiff was convicted and sentenced to two and a half years imprisonment for five counts of indecent dealing and indecent assault, with two of those counts relating to conduct occurring entirely before the plaintiff became an Australian citizen.

8. In July 2018, the Minister for Home Affairs, Immigration and Border Protection purportedly revoked the plaintiff's Australian citizenship under s 34(2) of the Australian Citizenship Act 2007 (Cth) ("the Citizenship Act") on the basis that the criterion in s 34(2)(b)(ii) of the Citizenship Act was satisfied: "the person has, at any time after making the application to become an Australian citizen, been convicted of a serious offence within the meaning of subsection (5)"[45]. At the date of citizenship revocation, the plaintiff had been an Australian citizen for 29 years and had lived in Australia continuously for 52 years. It had also been more than 15 years since the plaintiff's convictions for indecent dealing and indecent assault.

   [45]For ease of reference in these reasons, the power in s 34(2) in its operation with respect to the criterion in s 34(2)(b)(ii) is referred to generally as "the power in s 34(2)(b)(ii)".

9. Although the plaintiff was initially granted a visa upon revocation of his citizenship, that visa was cancelled in November 2021 by the Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs under s 501(2) of the Migration Act 1958 (Cth). In January 2022, the plaintiff was taken into immigration detention and remains there pending his removal from Australia. He has never returned to the United Kingdom since migrating from there to Australia, with his parents and siblings, as a teenager in 1966.

10. The plaintiff challenged the validity of s 34(2)(b)(ii) of the Citizenship Act on two grounds: first, that it is not supported by the "naturalization and aliens" head of power in s 51(xix) of the Constitution, and second, that it is contrary to Ch III of the Constitution because it reposes in the Minister administering the Citizenship Act the exclusively judicial function of punishing criminal guilt.

11. The questions stated for the opinion of the Full Court were narrow and limited. The facts and statutory framework are set out in the reasons of other members of the Court. I gratefully adopt them.

12. The dispositive issue is whether s 34(2)(b)(ii) confers on the Minister part of the judicial power of the Commonwealth – the imposition of punishment – contrary to Ch III of the Constitution. All members of this Court agree that that is addressed by asking whether the power in s 34(2)(b)(ii) is limited to what is reasonably capable of being seen as necessary for a legitimate non-punitive purpose[46] – in this case, the protection of the integrity of the naturalisation process. The answer is that it is not, and that s 34(2)(b)(ii) is therefore invalid. The plaintiff sought, and should be granted, a declaration that he is an Australian citizen.

    [46]See Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [38]-[39]; Reasons of Edelman J at [148]-[149]; Reasons of Steward J at [188]. See also Chu Kheng Lim v Minister for Immigration (1992) 176 CLR 1 at 33.

13. Given that conclusion, it is unnecessary to resolve the first ground of asserted invalidity. That ground, and the submissions of the defendants (together, "the Commonwealth") as to the scope of the head of power in s 51(xix), raise important issues that need not be addressed in this case[47]. It is sufficient to proceed on the basis that s 34(2)(b)(ii) is supported by the "naturalization and aliens" head of power in s 51(xix) of the Constitution because it is a law with respect to naturalisation.

    [47]See, eg, Alexander v Minister for Home Affairs (2022) 96 ALJR 560 at 589-594 [133]-[156]; 401 ALR 438 at 468-475.

    Statutory purpose of s 34(2)(b)(ii)

14. Identifying the purpose of s 34(2)(b)(ii) – and the manner in which it seeks to achieve its purpose – is essential to determining its validity under Ch III of the Constitution. Statutory purpose can be described as the "public interest sought to be protected and enhanced" by the law[48], which may be identified by reference to "the mischief" that the law seeks to redress[49]. Statutory purpose is not something which exists outside the statute; "[i]t resides in its text and structure"[50].

    [48]Cunliffe v The Commonwealth (1994) 182 CLR 272 at 300.

    [49]See, eg, APLA Ltd v Legal Services Commissioner (NSW) (2005) 224 CLR 322 at 394 [178]; McCloy v New South Wales (2015) 257 CLR 178 at 232 [132], 261 [232]; Brown v Tasmania (2017) 261 CLR 328 at 391-392 [208]-[210]; Unions NSW v New South Wales (2019) 264 CLR 595 at 657 [171]; LibertyWorks Inc v The Commonwealth (2021) 274 CLR 1 at 71 [183].

    [50]Lacey v Attorney-General (Qld) (2011) 242 CLR 573 at 592 [44]. See also Project Blue Sky Inc v Australian Broadcasting Authority (1998) 194 CLR 355 at 381 [69], 384 [78].

15. Section 34 is headed "Revocation by Minister – offences or fraud". Section 34(1) confers a discretionary power on the Minister to revoke the citizenship of a person who obtained citizenship by descent or by adoption under Subdiv A or AA of Div 2 of Pt 2 of the Citizenship Act. That power can be enlivened in two circumstances. The first is where the person has been convicted of an offence against s 50 of the Citizenship Act or s 137.1 or s 137.2 of the Criminal Code (Cth) in relation to their application to become an Australian citizen. Those offences relate to the giving of false or misleading statements or representations[51], the concealment of material circumstances[52], and the giving of false or misleading information[53] or documents[54]. The second is where the person obtained the Minister's approval to become an Australian citizen as a result of third-party fraud within the meaning of s 34(8) of the Citizenship Act[55]. In either circumstance, the Minister may only revoke citizenship if satisfied that it would be contrary to the public interest for the person to remain an Australian citizen[56].

    [51]Citizenship Act, s 50(1).

    [52]Citizenship Act, s 50(2).

    [53]Criminal Code, s 137.1.

    [54]Criminal Code, s 137.2.

    [55]Section 34(8) requires a relevant conviction and that the act or omission constituting the offence was connected with the Minister approving the applicant becoming an Australian citizen.

    [56]Citizenship Act, s 34(1)(c).

16. Section 34(2) confers a discretionary power on the Minister to revoke the citizenship of a person who obtained citizenship by conferral under Subdiv B of Div 2 of Pt 2 of the Citizenship Act[57]. That power can be enlivened in four circumstances. One of those circumstances is in s 34(2)(b)(ii), which is the provision challenged in this proceeding: "the person has, at any time after making the application to become an Australian citizen, been convicted of a serious offence within the meaning of subsection (5)".

    [57]Relevantly, under transitional provisions, a person who acquired Australian citizenship under Div 2 of Pt III of the 1948 Act is taken to be an Australian citizen under Subdiv B of Div 2 of Pt 2 of the Citizenship Act: Australian Citizenship (Transitionals and Consequentials) Act 2007 (Cth), Sch 3, items 1 and 2(2). See also Citizenship Act, s 4(1)(b).

17. Section 34(2)(b)(ii), read with the definition of "serious offence"[58], empowers the Minister to revoke the Australian citizenship of a person who obtained citizenship by conferral if, at any time after making the application to become an Australian citizen, the person is convicted of and sentenced to imprisonment of at least 12 months for an offence committed before the person became an Australian citizen. That power may only be exercised if the Minister is satisfied that it would be contrary to the public interest for the person to remain an Australian citizen[59]. The Minister must not decide to revoke a person's citizenship under s 34(2)(b)(ii) if the Minister is satisfied that the person would become a person who is not a national or citizen of any country[60]. If the Minister revokes a person's Australian citizenship, the person ceases to be an Australian citizen at the time of the revocation[61].

    [58]See Citizenship Act, s 34(5) (definition of "serious offence"), read with s 3 (definition of "serious prison sentence").

    [59]Citizenship Act, s 34(2)(c).

    [60]Citizenship Act, s 34(3).

    [61]Citizenship Act, s 34(4).

18. Two of the other circumstances in s 34(2) are the same as those under s 34(1): where the person has been convicted of an offence against s 50 of the Citizenship Act or s 137.1 or s 137.2 of the Criminal Code in relation to the person's application to become an Australian citizen (s 34(2)(b)(i)); and where the person obtained approval to become a citizen as a result of third-party fraud (s 34(2)(b)(iv)). The final circumstance is where the person obtained the Minister's approval to become an Australian citizen as a result of migration-related fraud within the meaning of s 34(6)[62] (s 34(2)(b)(iii)). To exercise the power in those circumstances, the Minister must also be satisfied that it would be contrary to the public interest for the person to remain an Australian citizen[63].

    [62]Section 34(6) requires a relevant conviction and that the act or omission that constituted the offence was connected with the person's entry into Australia or the grant to the person of a visa or permission to enter and remain in Australia. The meaning of "migration-related fraud" is further limited by s 34(7), which provides that s 34(6) does not apply to a person in respect of an offence if the Minister is satisfied that the act or omission that constituted the offence was not in any way (whether directly or indirectly) material to the person becoming a permanent resident.

    [63]Citizenship Act, s 34(2)(c).

19. It is apparent that the purpose of s 34, in most of its operations, is to protect the integrity of the naturalisation process by enabling the revocation of citizenship in circumstances where it was obtained as a result of fraud or false or misleading statements connected to the person's citizenship application or grant of citizenship or entry into Australia. Section 34(2)(b)(ii) differs from the other provisions in s 34(1)(b) and (2)(b) by not having this clear connection to the integrity of the naturalisation process.

20. The Commonwealth accepted that, unlike the other provisions, s 34(2)(b)(ii) may be enlivened even if the relevant offending is not directly causative of a person's acquisition of citizenship. The Commonwealth submitted that nevertheless the purpose of s 34(2)(b)(ii), like the other provisions in s 34(1)(b) and (2)(b), is to protect the integrity of the naturalisation process. Why? A person is only eligible to become an Australian citizen under Subdiv B of Div 2 of Pt 2 of the Citizenship Act if the Minister is satisfied that the person is of good character at the time of the Minister's decision on the application[64]. Section 34(2)(b)(ii) only applies to offending conduct engaged in prior to the grant of citizenship that is sufficiently serious to result in a sentence of imprisonment of at least 12 months, and where the conviction occurred after the application was made to become an Australian citizen. Although, unlike the other provisions in s 34(1)(b) and (2)(b), s 34(2)(b)(ii) does not require fraud, concealment or dishonesty in the acquisition of citizenship, it is directed to a different kind of mischief. The Commonwealth's submission was that the mischief to which s 34(2)(b)(ii) is directed is the "gap" created by the possibility of criminal conduct, occurring before the grant but not known about at the time of the grant, that is clearly relevant to the good character criterion of eligibility for citizenship.

    [64]Citizenship Act, s 21(2)(h).

21. Those submissions should be accepted. That identification of the statutory purpose is consistent with the text, context and legislative history[65] of s 34(2)(b)(ii). It is also consistent with relevant extrinsic materials: a Ministerial Statement to the House of Representatives in 1982[66] and the second reading speech for the Australian Citizenship Amendment Act1984 (Cth)[67]. As the Commonwealth submitted, the purpose of the power in s 34(2)(b)(ii) is to protect the integrity of the naturalisation process by ensuring that accidents of timing do not allow decisions about naturalisation to be made irrevocably on incorrect and incomplete information, and to provide a disincentive for an applicant for citizenship to conceal their prior criminal conduct or to rush to secure citizenship before that conduct is revealed.

    [65]See Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [14]-[19], [26], [33].

    [66]See Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [17], referring to Australia, House of Representatives, Parliamentary Debates (Hansard), 6 May 1982 at 2361.

    [67]See Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [18], referring to Australia, House of Representatives, Parliamentary Debates (Hansard), 7 December 1983 at 3369.

22. However, that identified statutory purpose is not the end of the inquiry for the asserted invalidity under Ch III. Indeed, the plaintiff came to accept that protection of the integrity of the naturalisation process could be described as the purpose of all the provisions in s 34(1)(b) and (2)(b), but submitted that once s 34(2)(b)(ii) was properly characterised for the purposes of the constitutional inquiry, that was not its "true" purpose, or in other words it pursued that purpose in a way which transgressed the constitutional boundary.

    Chapter III of the Constitution

23. The Constitution "is based upon a separation of the functions of government, and the powers which it confers are divided into three classes – legislative, executive and judicial"[68], as set out in its first three chapters. Chapter III of the Constitution sets out an exhaustive statement of the manner in which the judicial power of the Commonwealth is or may be vested[69]. In so doing, Ch III places limits on judicial, legislative and executive power[70].

    [68]In re Judiciary and Navigation Acts (1921) 29 CLR 257 at 264. See also Davis v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs (2023) 97 ALJR 214 at 231‑232 [68]-[71]; 408 ALR 381 at 399-400.

    [69]R v Kirby; Ex parte Boilermakers' Society of Australia (1956) 94 CLR 254 at 270.

    [70]Boilermakers' (1956) 94 CLR 254 at 268-270, 273, 276, 279. See also Wilson v Minister for Aboriginal and Torres Strait Islander Affairs (1996) 189 CLR 1 at 10, 16-17, 20, 26; Private R v Cowen (2020) 271 CLR 316 at 369 [139]-[140], 370-371 [142]-[144]; The Commonwealth v AJL20 (2021) 273 CLR 43 at 83-84 [78]-[80], 84‑85 [83]-[84], 95 [106]‑[107], 98 [114], 106-107 [137]. See also Victoria v The Commonwealth and Hayden (1975) 134 CLR 338 at 380; Attorney-General (NSW) v Quin (1990) 170 CLR 1 at 35-36; Plaintiff S157/2002 v The Commonwealth (2003) 211 CLR 476 at 504-505 [71]-[73], 513-514 [104].

1. Punishment for criminal guilt is an exclusively judicial function under the Constitution[71]. A law purporting to empower the Executive to deprive a person of nationality and citizenship may be invalid on that basis[72]. Not all hardship or distress inflicted upon a person constitutes punishment[73]. That a law permits denationalisation and deprivation of citizenship does not necessarily dictate the conclusion that the law is punitive[74].

   [71]Benbrika v Minister for Home Affairs ("Benbrika [No 2]") [2023] HCA 33 at [33]‑[35], [60], [69], [89]-[90], affirming Lim (1992) 176 CLR 1 at 27.

   [72]Alexander (2022) 96 ALJR 560; 401 ALR 438; Benbrika [No 2] [2023] HCA 33.

   [73]Re Woolley; Ex parte Applicants M276/2003 (2004) 225 CLR 1 at 12 [17].

   [74]Alexander (2022) 96 ALJR 560 at 613 [249]; 401 ALR 438 at 500.

2. As I explain in Benbrika v Minister for Home Affairs ("Benbrika [No 2]")[75], it should be accepted, following Chu Kheng Lim v Minister for Immigration[76] and Alexander v Minister for Home Affairs[77], that absent a legitimate non-punitive purpose, the default characterisation of a law providing for non‑consensual denaturalisation, denationalisation or deprivation of citizenship will be that it is punitive. That is because, like detention – and indeed perhaps to a greater degree – the deprivation of nationality and citizenship imposes profound detriment on the individual. Detention may only be a temporary loss of rights and liberty. Deprivation of nationality and citizenship is a permanent rupture in the relationship between the individual and the State, involving loss of fundamental rights including by exposure to detention and deportation from the territory[78].

   [75][2023] HCA 33 at [63]-[65]. See also Alexander (2022) 96 ALJR 560 at 578 [72]‑[73], 579 [76]-[77], 583 [95], 583 [98], 597 [166], 613 [248]; 401 ALR 438 at 454, 455-456, 460, 461, 478, 500. See also Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [38]-[39], [43]; Reasons of Edelman J at [148]‑[149]; Reasons of Steward J at [188].

   [76](1992) 176 CLR 1.

   [77](2022) 96 ALJR 560; 401 ALR 438.

   [78]See Benbrika [No 2] [2023] HCA 33 at [63]. See also Migration Act, ss 13(1), 14(1), 189(1), 196(1), 198.

3. Like a law authorising detention, a law for involuntary denationalisation and citizenship deprivation will be valid if it is limited to what is reasonably capable of being seen as necessary for a legitimate non‑punitive purpose[79]. The plaintiff was correct to identify this as being the relevant test, drawing on Lim[80]. The Commonwealth's argument that the test in Lim does not apply is rejected. As a default characterisation, involuntary denationalisation and citizenship stripping is punitive. A law that empowers involuntary denationalisation and citizenship stripping must be justified.

   [79]See Lim (1992) 176 CLR 1 at 33-34; see also 10, 58, 65-66, 71. See also Kruger v The Commonwealth (1997) 190 CLR 1 at 162; Plaintiff M76/2013 v Minister for Immigration, Multicultural Affairs and Citizenship (2013) 251 CLR 322 at 369 [138]; Plaintiff S4/2014 v Minister for Immigration and Border Protection (2014) 253 CLR 219 at 231 [25]-[26]; Plaintiff M68/2015 v Minister for Immigration and Border Protection (2016) 257 CLR 42 at 86 [98], 130 [260], 160 [379]-[381]; Falzon v Minister for Immigration and Border Protection (2018) 262 CLR 333 at 343 [27], 343-344 [29], 355-356 [82]; Minister for Home Affairs v Benbrika ("Benbrika [No 1]") (2021) 272 CLR 68 at 96 [32], 113 [78], 119 [95], 138 [151], 141 [160], 142 [163], 147 [177], 168-169 [225]; AJL20 (2021) 273 CLR 43 at 64‑65 [27], 83 [79], 102 [127]-[128]. See also Fardon v Attorney-General (Qld) (2004) 223 CLR 575 at 653-654 [215]; Vella v Commissioner of Police (NSW) (2019) 269 CLR 219 at 287 [171], 288 [174], 292 [187], 294-295 [195]-[200]; Garlett v Western Australia (2022) 96 ALJR 888 at 918 [143], 926-927 [179]-[180], 930 [190]-[191], 944 [257]‑[258], 954 [313]; 404 ALR 182 at 215, 224-225, 228-229, 246, 260.

   [80](1992) 176 CLR 1.

4. The central point made by the Commonwealth was that s 34(2)(b)(ii) does not confer judicial power – the imposition of punishment – because it is a provision for the protection of the integrity of the naturalisation process. Protection of the integrity of the naturalisation process is a legitimate non-punitive purpose – it reflects that it is a well-recognised attribute of sovereignty that every nation state is entitled to decide what aliens shall or shall not become members of its community[81]. As explained above, the protection of the integrity of the naturalisation process broadly can be described as the purpose of s 34(2)(b)(ii). However, in the context of the Ch III inquiry, s 34(2)(b)(ii) can only be said to properly have that non‑punitive purpose if it is limited to what is reasonably capable of being seen as necessary for that purpose[82]. Put in other words, if s 34(2)(b)(ii) pursues its purpose in a manner incompatible with the doctrine of the separation of judicial power under Ch III, or if the provision is not sufficiently tailored to the achievement of its purpose, then it is not properly characterised or justified as non‑punitive[83]. The application of the Lim principle therefore requires an assessment of the relationship between means and ends. Labels such as "proportionality" are misleading to the extent that they import notions of structured proportionality[84].

   [81]Alexander (2022) 96 ALJR 560 at 590 [138]; 401 ALR 438 at 470, and the authorities there cited.

   [82]See Falzon (2018) 262 CLR 333 at 343-344 [29].

   [83]See Alexander (2022) 96 ALJR 560 at 585 [106]; 401 ALR 438 at 463. See also, in the context of powers conferred on courts to make preventative orders for detention or imposing other constraints on liberty: Vella (2019) 269 CLR 219 at 279 [151], 287 [171], 292 [187], 294-295 [195]-[200]; Benbrika [No 1] (2021) 272 CLR 68 at 138 [151], 142 [163], 146 [173], 147 [177]; Garlett (2022) 96 ALJR 888 at 918 [143], 926 [179], 930 [190]-[191]; 404 ALR 182 at 215, 224-225, 228-229.

   [84]See Falzon (2018) 262 CLR 333 at 343-344 [29]-[31].

5. In considering whether the power in s 34(2)(b)(ii) is contrary to Ch III, it is important to consider whether the provision reflects a condition imposed on the plaintiff's naturalisation. As I stated in Alexander[85], "in respect of a law conferring power on the Minister to cancel a person's citizenship if they obtained citizenship by making false statements or engaging in fraudulent conduct, denaturalisation might be more properly characterised as the consequence of breaching a condition imposed on the person's entry into the community, rather than punishment".

   [85](2022) 96 ALJR 560 at 599 [174]; 401 ALR 438 at 481, referring to Trop v Dulles (1958) 356 US 86 at 98-99.

6. At the time the plaintiff was granted citizenship, he had to satisfy the Minister he was of good character[86], and there was a power in the 1948 Act (relevantly equivalent to the power in s 34(2)(b)(ii) of the Citizenship Act) for citizenship to be revoked if a person was convicted, after furnishing their application for the certificate of citizenship, of an offence committed prior to the grant for which the person had been sentenced to imprisonment for at least 12 months[87]. That predecessor power in the 1948 Act, continued by s 34(2)(b)(ii) of the Citizenship Act, was in force at the time of the grant of the plaintiff's citizenship and remains a power only applying in respect of any offending before the grant of citizenship where the conviction was not until after the making of the application for citizenship. It was and is a condition and power in respect of which the plaintiff can be taken to have been on notice at the time of his application for citizenship and the time of grant of citizenship.

   [86]1948 Act (as in force at time of grant of plaintiff's citizenship), s 13(1)(f).

   [87]1948 Act (as in force at time of grant of plaintiff's citizenship), s 21(1).

7. As explained, the Commonwealth argued that s 34(2)(b)(ii) protects the integrity of the naturalisation process in two ways: first, by ensuring that accidents of timing do not allow decisions about naturalisation to be made irrevocably on incorrect or incomplete information; second, by providing a disincentive for an applicant for citizenship to conceal their prior criminal conduct or to rush to secure citizenship before that conduct is revealed.

8. The plaintiff, on the other hand, submitted that the following features of s 34(2)(b)(ii) disclosed a "significant disconformity" between the operation of s 34(2)(b)(ii) and the protective purpose postulated by the Commonwealth.

9. First, the plaintiff submitted that the application of s 34(2)(b)(ii) is indifferent to the integrity of the naturalisation process in that it applies whether or not the conduct to which the offence relates was disclosed at the time of the application; whether or not the applicant was even invited or required to make disclosure of such matters at the time; and whether or not the conduct would have necessarily precluded the grant of citizenship. The plaintiff relied on the fact that the power in s 34(2)(b)(ii) is enlivened by a broad range of offending conduct having no necessary connection to the naturalisation process. By contrast, the other provisions in s 34(1)(b) and (2)(b) require a person to have been convicted of an offence for dishonesty or concealment in relation to their citizenship application or that the person obtained the Minister's approval to become a citizen as a result of fraud. The plaintiff submitted that the purpose which the Commonwealth ascribed to s 34(2)(b)(ii) – protecting the integrity of the naturalisation process – is already pursued by those other provisions. Further, the plaintiff submitted that those other provisions are tailored to the purpose because the necessary fraud, concealment or dishonesty is causally linked to the grant of citizenship. By contrast, the plaintiff submitted, s 34(2)(b)(ii) effectively "deem[s]" that the serious offending would have precluded the grant of citizenship.

10. It may be accepted that the other provisions in s 34(1)(b) and (2)(b) are more closely tailored to the purpose of protecting the integrity of the naturalisation process. However, this does not necessarily lead to invalidity of s 34(2)(b)(ii). The other provisions are dealing with a different mischief – fraud, dishonesty or concealment in the naturalisation process[88]. And it is not right to contend that revocation for fraud, dishonesty or concealment in the naturalisation process is the only permissible means of protecting the integrity of the naturalisation process. Parliament may wish to protect the integrity of the naturalisation process by addressing another mischief: the "gap" created by the possibility of criminal conduct occurring before the grant, relevant to the good character criterion of eligibility, that is not known about at the time of grant. That "gap" might be addressed by imposing a requirement on an applicant for citizenship to disclose criminal conduct, such that a failure to disclose that conduct would engage offence provisions for fraud, dishonesty or concealment. Or it might be addressed by provisions similar to those in the United States[89], which require that naturalisation be proved to have been "illegally procured" (that the person was statutorily ineligible to naturalise at the time they became a naturalised citizen)[90] or procured "by concealment of a material fact or by willful misrepresentation"[91]. Or the "gap" might be addressed by other means. The Parliament of the Commonwealth, in enacting s 34(2)(b)(ii), has adopted a different legislative framework. That was a choice that was open to the Parliament, provided that the means by which the "gap" was sought to be addressed are limited to what is reasonably capable of being seen as necessary to protect the integrity of the naturalisation process.

    [88]That s 34(2)(b)(ii) is addressing a different issue to the other provisions in s 34(1)(b) and (2)(b) is reinforced by the fact that s 34(3) only applies to s 34(2)(b)(ii) and not the other provisions. That limitation reflects the Convention on the Reduction of Statelessness.

    [89]See 8 USC §1451(a) (emphasis added).

    [90]See Fedorenko v United States (1981) 449 US 490 at 506.

    [91]See Kungys v United States (1988) 485 US 759 at 767. See also Maslenjak v United States (2017) 137 S Ct 1918.

11. Second, the plaintiff submitted that s 34(2)(c) (the public interest criterion) requires consideration not of whether the person was of good character at the time of grant or whether the person would not have been granted citizenship had the offending been known, but instead whether it presently would be contrary to the public interest for the person to remain a citizen. This forward‑looking assessment was said to invite consideration of a broad range of matters having nothing to do with good character at the time of the grant or the protection of the integrity of the naturalisation process.

12. The Commonwealth submitted that, properly construed, the public interest criterion is an additional hurdle for the Minister and provides some benefit for the person. As an additional hurdle it reflects that the object of protecting the integrity of the naturalisation process is not cut and dried; it may be nuanced and, in the words of Ms Gordon KC for the Commonwealth, "ought not to be pursued at any cost, given the harshness of the consequences". But, as will be explained, that submission overstates the degree to which the public interest criterion is capable of moulding and limiting the exercise of the power in a manner consistent with its purpose.

13. Third, the plaintiff relied on the absence of time limits between naturalisation and exercise of the power, and between conviction and exercise of the power. There is a built-in time limit to the power: the offence must have been committed before naturalisation and the conviction must have occurred after the making of the application for citizenship. Further, the lack of a time limit between naturalisation and exercise of the power reflects that it can take many years to detect criminal conduct and it is unpredictable as to when criminal offences are detected and convictions secured.

14. That leaves the lack of a time limit between conviction and exercise of the power, which is particularly pertinent here, where there was a 15 year gap between the plaintiff's conviction in 2003 and the Minister's decision in 2018. The plaintiff submitted that a time limit from the date of conviction would show that the provision was aimed at enabling the Minister to respond to new information – the conviction for pre-naturalisation conduct – which might call the grant of citizenship into question. The plaintiff submitted that, where the power to revoke is of unlimited duration after conviction, that tells against the protective purpose because s 34(2)(b)(ii) enables denaturalisation to occur even where (as here) the facts of the criminal conviction and sentence have been a matter of public record for decades.

15. The default characterisation that revocation of naturalisation is punitive is not displaced, but is reinforced, by the legal and practical operation of s 34(2)(b)(ii). In particular, it is reinforced by considering, as an aspect of the power, the period of time during which the power may be exercised[92].

    [92]See, by analogy, AJL20 (2021) 273 CLR 43 at 83-84 [80], citing Plaintiff S4 (2014) 253 CLR 219 at 232 [29]. See also AJL20 (2021) 273 CLR 43 at 65 [28], 83 [79], 86-87 [87], 91 [97].

16. Section 34(2)(b)(ii) leaves the class of naturalised citizens to whom it applies – persons who became citizens by conferral and who have since been convicted of a "serious offence" within the meaning of s 34(5) – at permanent risk of the revocation of their nationality and citizenship. The Executive could "scour [the] paperwork" to find naturalised citizens in that class and at any time purport to revoke their nationality and citizenship under s 34(2)(b)(ii) on the basis of ministerial public interest satisfaction, affording those naturalised Australians "precious little security"[93]. The presence of s 34(2)(b)(ii) on the statute books makes such a naturalised citizen liable, for the rest of their life, to potential expulsion from the nation. It is not only the exercise of the power, but the presence of the power, which hurts[94]. Section 34(2)(b)(ii) exposes a naturalised citizen who has been convicted of a "serious offence" to revocation of naturalisation beyond the limits necessary for the protection of the integrity of the naturalisation process[95].

    [93]See, by analogy, Maslenjak (2017) 137 S Ct 1918 at 1927.

    [94]See Australia, House of Representatives, Parliamentary Debates (Hansard), 26 August 1958 at 711. 

    [95]See, by analogy, AJL20 (2021) 273 CLR 43 at 83 [79], citing Lim (1992) 176 CLR 1 at 33-36.

17. The Commonwealth's only response to the plaintiff's submissions about the lack of a time limit after conviction was to submit that "the passage of time and any significance that ought to be attributed to that, is the very thing – not the very thing, one of the things that can be taken into account [for the purposes of ministerial public interest satisfaction under s 34(2)(c)]". The Commonwealth's submission was that the public interest criterion in s 34(2)(c) limited the exercise of the power in s 34(2)(b)(ii) in a way which would prevent it being used for punitive purposes or with punitive effect. The Commonwealth rejected the suggestion that the absence of any statutory prescription of time within which revocation might occur after conviction bore upon questions of validity of the provision. That submission amounted to saying that citizenship could be revoked under s 34(2)(b)(ii) no matter how long before revocation the person concerned had been convicted of an offence which they had committed before naturalisation but for which they had been tried and convicted after making the application for naturalisation. That is, no matter how long had elapsed since the conviction, the revocation was, and was capable of being, for the purpose of protecting the integrity of the naturalisation process.

18. The greater the amount of time between conviction and revocation, the less revocation has to do with the state of affairs that existed at the time of naturalisation and the processes undertaken for that purpose, and the less it has to do with the conviction and the extent to which that conviction brings into question the integrity of the process of naturalisation. This case is illustrative. Whilst acknowledging that the plaintiff did not seek judicial review of the Minister's decision in this proceeding, one might ask what the revocation of the plaintiff's citizenship 15 years after conviction had to do with protecting the naturalisation process.

19. The Commonwealth rightly said that this Court cannot and should not try to mark the point at which the boundary of protecting the process of naturalisation is passed. But it is not right to say that the public interest criterion in s 34(2)(c) confines the application of the power to circumstances that do not infringe Ch III. Section 34(2)(c) does not save s 34(2)(b)(ii). "Public interest" is too wide a concept. Section 34(2)(c) asks the Minister to consider reasons why it might now be contrary to the public interest for the person to remain an Australian citizen. As other members of the Court observe, the expression "in the public interest", when used in a statute, "classically imports a discretionary value judgment to be made by reference to undefined factual matters, confined only 'in so far as the subject matter and the scope and purpose of the statutory enactments may enable ... given reasons to be [pronounced] definitely extraneous to any objects the legislature could have had in view'"[96]. That is, formation of the satisfaction under s 34(2)(c) may be confined only by what is excluded, namely reasons or considerations that are extraneous or forbidden. The "public interest" does not require consideration of any particular matter. As the Commonwealth's submissions necessarily accepted, how much time had elapsed between conviction and revocation would be only one circumstance among many others that might go to inform ministerial satisfaction about the public interest. And the power in s 34(2) does not contain any other criteria that would structure or constrain the exercise of the Minister's discretion in a manner consistent with the asserted purpose of s 34(2)(b)(ii).

    [96]O'Sullivan v Farrer (1989) 168 CLR 210 at 216, quoting Water Conservation and Irrigation Commission (NSW) v Browning (1947) 74 CLR 492 at 505, quoted in Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [21] and Reasons of Steward J at [201].

1. As to the third group of submissions, unless the narrowness of the power based on the gateway in s 34(2)(b)(ii) were so extreme as to suggest that the power had no sufficient or rational connection with the protection of the integrity of the naturalisation process, it could not be an objection to the power being reasonably capable of being seen as necessary for that purpose that the Commonwealth Parliament has chosen a less expansive law than it might otherwise have chosen in order to fulfil that purpose.

2. It is, therefore, no objection that Parliament excluded from the Minister's power to revoke citizenship those instances of naturalisation by descent or adoption or those circumstances where revocation would cause Australia to be in breach of its international obligations. Nor, in light of the interpretation of s 34(2)(c) explained above, can it be any objection that a further condition for revocation is the Minister's satisfaction that it would be contrary to the public interest for the person to remain an Australian citizen. Rather, as explained above, the application of s 34(2)(c) will necessarily be confined to the purpose of protecting the integrity of the naturalisation process.

   Conclusion

3. The questions in the special case should be answered as follows:

   (1)Is s 34(2)(b)(ii) of the Australian Citizenship Act invalid in its operation in respect of the plaintiff because:

   (a)it is not supported by s 51(xix) of the Constitution; or

   (b)it reposes in the Minister the exclusively judicial function of punishing criminal guilt?

   Answer:No.

   (2)What, if any, relief should be granted to the plaintiff?

   Answer:None.

   (3)       Who should pay the costs of the special case?

   Answer:The plaintiff.

4. STEWARD J.   The plaintiff was born in the United Kingdom of Great Britain and Northern Ireland in 1950. He migrated to Australia in 1966. On 21 December 1988, he acquired Australian citizenship pursuant to the Australian Citizenship Act 1948 (Cth) ("the Old Citizenship Act"). In 2003, the plaintiff was convicted of five counts of indecent dealing and indecent assault, some of which occurred before he became a citizen of Australia. Two events have since taken place as a result of the plaintiff's offending. First, in 2018 the Minister for Home Affairs, Immigration and Border Protection revoked the plaintiff's citizenship pursuant to s 34(2) of the Australian Citizenship Act 2007 (Cth) ("the Present Citizenship Act"). Thereafter, the plaintiff held an ex‑citizen visa which permitted him to remain in Australia. Secondly, in 2021 the Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs cancelled the plaintiff's ex-citizen visa. Thereafter, the plaintiff assumed the status of an unlawful non-citizen who is to be deported. This special case concerns only the first decision. In particular, the plaintiff challenges the validity of s 34(2)(b)(ii) of the Present Citizenship Act.

5. It should initially be observed that the immediate effect of revoking the plaintiff's citizenship was not to expose him to immigration detention pending deportation to the United Kingdom. His ex‑citizen visa was a permanent visa which permitted him to remain lawfully in Australia (but not to re-enter this country). Rather, the denationalisation of the plaintiff had the consequence of disentitling the plaintiff from the statutory benefits which attach to a person by reason of being an Australian citizen. When the plaintiff's ex‑citizen visa was cancelled in 2021, he lost the right to remain here and became subject to detention pending deportation. This Court has previously decided that a law which authorises the cancellation of a visa, thereby making one liable to this form of detention, does not involve the imposition of any punishment and is therefore valid[210].

   [210]Falzon v Minister for Immigration and Border Protection (2018) 262 CLR 333 at 351 [63] per Kiefel CJ, Bell, Keane and Edelman JJ, 352 [69] per Gageler and Gordon JJ, 358 [93] per Nettle J.

6. For the short reasons which follow, I agree with Kiefel CJ, Gageler, Gleeson and Jagot JJ that s 34(2)(b)(ii) of the Present Citizenship Act is a valid law of the Commonwealth. It does not offend the principle established by this Court in Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs that the power to punish a person by way of retribution, denunciation or deterrence is exclusively judicial[211]. That is because, properly characterised, s 34(2)(b)(ii) is reasonably capable of being seen as necessary for the legitimate non-punitive purpose of protecting the integrity of the naturalisation process. As was conceded in oral argument by the plaintiff, in the circumstances of this case, that conclusion also disposes of the plaintiff's attack on s 34(2)(b)(ii) as being unsupported by the "naturalization" limb of s 51(xix) of the Constitution.

   [211](1992) 176 CLR 1 at 27 per Brennan, Deane and Dawson JJ.

   The "good character" condition

7. It has long been a condition of naturalisation in this country[212], and others[213], that an applicant be of good repute or good character. Thus, from 1903 a person seeking a certificate of naturalisation was required to obtain a certificate from a Justice of the Peace, a postmaster, a teacher or a police officer confirming that he or she was a "person of good repute": s 6(1)(b) of the Naturalization Act 1903 (Cth). From 1920, a person seeking a certificate of naturalisation needed to satisfy the Governor‑General that he or she was of "good character": s 7(1)(b) of the Nationality Act1920 (Cth). When the plaintiff sought citizenship of Australia in 1988 under the Old Citizenship Act, he also needed to be a person of "good character": s 13(1)(f) of the Old Citizenship Act. The need for a person to be of "good character", as a condition of naturalisation, remains to this day: s 21(2)(h) of the Present Citizenship Act.

   [212]And, indeed, prior to Federation: see, eg, Aliens Act 1863 (SA), s 7; Aliens Act 1864 (SA), s 9; Aliens Act 1890 (Vic), ss 5 and 7.

   [213]See, eg, Aliens Act 1866 (NZ), ss 5 and 7; Aliens Act 1880 (NZ), s 4; Naturalization Act 1906 (US), s 4.

8. As the reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ explain, any past offending by an applicant for citizenship would plainly be relevant to issues of good character. But such offending would not necessarily be determinative of that issue. As Latham CJ observed in Inre Davis[214]:

   "A man may be guilty of grave wrongdoing and may subsequently become a man of good character."

   [214](1947) 75 CLR 409 at 416. See also Minister for Immigration and Multicultural Affairs v Jia Legeng (2001) 205 CLR 507 at 529-530 [65] per Gleeson CJ and Gummow J.

9. The plaintiff did not challenge the validity of any law which conditioned the acquisition of citizenship upon a person being of "good character". The imposition of such a condition amply falls within the legislative power to pass laws concerning "naturalization" for the purposes of s 51(xix) of the Constitution. Nor was it suggested that the quality of being of "good character" was confined to a consideration only of the conduct of a person in applying for citizenship. Critically, there was thus no suggestion that only certain types of past offending could be relevant to the issue of having a "good character".

10. Australian naturalisation legislation has also long recognised that undisclosed offending which takes place before a grant of naturalisation or citizenship, but which is discovered later, may be a legitimate ground for the denationalisation of a person. The legitimacy arises from the same condition that a person be of "good character" when seeking membership of the Australian community. A person seeking naturalisation who is ostensibly of good character, but who has committed a very serious crime or crimes which have yet to be uncovered, may fail this condition.

11. Thus, s 12(2)(c) of the Nationality Act 1920 relevantly provided that the Governor-General could revoke a person's certificate of naturalisation if the Governor‑General was satisfied that the person was not, when naturalised, of good character. Section 12(2)(b) conferred the same power of revocation where the person had, within five years after naturalisation, been sentenced in "any court in His Majesty's dominions" to a term of imprisonment of not less than 12 months, or to a term of "penal servitude", or to a fine of not less than 100 pounds. In each case the power could only be exercised if the Governor-General was satisfied that it would not be conducive to the public good for the person to continue to hold a certificate of naturalisation.

12. Similar powers of denationalisation were also originally conferred by s 21 of the Old Citizenship Act[215]. Section 21(1)(d) was in near identical terms to s 12(2)(c) of the Nationality Act 1920, whilst s 21(1)(e) conferred a power of citizenship deprivation where the person had, within five years after naturalisation, been sentenced "in any country" to a term of imprisonment of 12 months or more. Those provisions were repealed in 1958[216] and replaced with a narrower power of citizenship deprivation limited to conviction for a particular offence of knowingly making a false statement, or concealing a material circumstance, for a purpose of or in relation to the Old Citizenship Act[217]. However, in 1984, the power was expanded to conviction, whether in Australia or overseas, at any time after the furnishing of an application for citizenship, of an offence, committed before the person was granted a certificate of Australian citizenship, for which that person had, relevantly, been sentenced to imprisonment for a period of not less than 12 months[218].

    [215]Then titled the Nationality and Citizenship Act 1948 (Cth).

    [216]Nationality and Citizenship Act 1958 (Cth), s 7.

    [217]Section 50 of the Old Citizenship Act, as amended by the Nationality and Citizenship Act 1958 (Cth), s 11. A public interest test also needed to be satisfied.

    [218]Australian Citizenship Amendment Act 1984 (Cth), s 15.

13. Section 34(2)(b)(ii) of the Present Citizenship Act is the successor to these provisions. It permits the Minister to revoke the citizenship of a naturalised person where the person has, at any time after the making of an application for citizenship, been convicted of a "serious offence". The term "serious offence" is defined in s 34(5) and refers to being convicted of an offence against Australian or foreign law, committed at any time before the person became a citizen, for which the person has been sentenced to death or to a serious prison sentence, defined in s 3 to mean a term of imprisonment for a period of at least 12 months. Before this power can be exercised the Minister must be satisfied that it would be contrary to the public interest for the person to remain an Australian citizen[219].

    [219]Present Citizenship Act, s 34(2)(c).

    The purpose of s 34(2)(b)(ii)

14. If s 51(xix) of the Constitution validly supports a law that conditions naturalisation upon the need for an applicant for citizenship to be of "good character", it must follow that laws which address the potential for the true character of a person to be masked during the application process must also be valid. The latter type of law, to use the language of Kiefel CJ, Gageler, Gleeson and Jagot JJ, protects the integrity of the naturalisation process by which a Minister is properly satisfied that an applicant is of good character. Indeed, the plaintiff's counsel accepted that laws truly of this type could not be characterised as punitive in nature.

15. The dispositive question in this special case is thus whether s 34(2)(b)(ii) is a law of this type. The plaintiff submitted that it was not. He submitted that the law is not reasonably capable of being characterised as necessary for the purpose of protecting the integrity of the naturalisation process. Substantially for the reasons given by Kiefel CJ, Gageler, Gleeson and Jagot JJ, I respectfully disagree[220].

    [220]This is not to be taken as an expression of agreement with all of the authorities cited by Kiefel CJ, Gageler, Gleeson and Jagot JJ, such as Trop v Dulles (1958) 356 US 86, Alexander v Minister for Home Affairs (2022) 96 ALJR 560; 401 ALR 348 and Benbrika v Minister for Home Affairs [2023] HCA 33.

16. Some additional observations should be made. There are three aspects of the power conferred by s 34(2)(b)(ii) which arguably support the proposition that it is not reasonably capable of being seen as necessary for a legitimate non-punitive purpose. The first is that, unlike s 12(2)(b) of the Nationality Act 1920 and the original s 21(1)(e) of the Old Citizenship Act, there is no temporal limitation on when a naturalised person may be convicted of a serious offence that will then engage the power of revocation. Secondly, unlike the version of s 21 of the Old Citizenship Act enacted in 1958[221], the definition of "serious crime" is arguably too broad; it is not tied to crimes relating to the process whereby naturalisation is sought. It is unlike, for example, s 34(2)(b)(iii) of the Present Citizenship Act, which confers a power of revocation where there has been "migration-related fraud", as defined by s 34(6). And thirdly, there is no time limit within which a relevant Minister may exercise the power of revocation following conviction of a serious crime. As Gordon J points out, here the power was exercised 15 years after the plaintiff's conviction.

    [221]See Nationality and Citizenship Act 1958 (Cth), s 7.

17. The first aspect is largely answered by Kiefel CJ, Gageler, Gleeson and Jagot JJ with the observation that s 34(2)(b)(ii) does not authorise the revocation of citizenship for purposes of retribution, denunciation or deterrence[222]. But I would also add that it is not unreasonable to expose a person to the threat of denationalisation where they have committed, before becoming a citizen, a "serious" crime that, if it had been disclosed at the time of application, is likely to have led the Minister to have concluded that the person was not of good character. Moreover, it is now well known that some crimes, such as child sexual abuse, can take many, many years before they are prosecuted with a resulting conviction. In the context of the need to preserve the soundness of new membership of the Australian polity, the lack here of any temporal limitation on when a conviction must take place does not demonstrate the presence of a different purpose, namely to punish a naturalised person.

    [222]Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [54]-[55].

18. The second aspect is more difficult. The naturalisation power in s 51(xix) confers a broad power within which Parliament is free to make legislative choices about, relevantly, the integrity of the naturalisation process. Thus, for example, it might have been open to Parliament to have adopted a form of s 12(2)(c) of the Nationality Act 1920 or the original s 21(1)(d) of the Old Citizenship Act whereby citizenship is revoked if it is subsequently found that a person was not of good character when he or she applied for citizenship. Instead, Parliament has chosen a somewhat arbitrary analogue of this type of power. There is a latent assumption within s 34(2)(b)(ii), when combined with s 34(2)(c), that a person who has been convicted of the sort of pre-citizenship offence that merits a prison sentence of at least 12 months was not of good character when he or she applied to become a citizen. However, I do not think that assumption militates against a conclusion that s 34(2)(b)(ii) is reasonably capable of being seen as necessary for the protection of the integrity of the naturalisation process. It is simply the expression of a legislative choice about how best to preserve that integrity.

19. That is so for a number of reasons. First, as mentioned above, it was not suggested that only certain types of offending could be considered by the Minister when assessing the presence of "good character" for the purposes of s 21(2)(h) of the Present Citizenship Act. Given that s 34(2)(b)(ii) is intended to address offending which had not been disclosed prior to a person becoming a citizen, it would make little sense to confine its scope to only those offences associated with the application process for naturalisation. Secondly, the types of convictions that may engage s 34(2)(b)(ii) are not unconfined; they are limited to convictions for serious offences. In that respect, and as already mentioned, it is not unreasonable to assume that a person is unlikely to have been of good character if, before becoming a citizen, he or she had committed an offence or offences that subsequently merited a prison sentence of at least 12 months. Thirdly, even if in some cases such an assumption is found to be wrong, the legislative scheme precludes any unnecessarily harsh outcome. That is because of the need for the Minister to be satisfied that it is in the "public interest" for the person not to remain a citizen before the power of revocation can be exercised. As Kiefel CJ, Gageler, Gleeson and Jagot JJ observe, what is or is not in the public interest[223]:

    "classically import[ed] a discretionary value judgment to be made by reference to undefined factual matters, confined only 'in so far as the subject matter and the scope and purpose of the statutory enactments may enable ... given reasons to be [pronounced] definitely extraneous to any objects the legislature could have had in view'".

    [223]Reasons of Kiefel CJ, Gageler, Gleeson and Jagot JJ at [21], quoting O'Sullivan v Farrer (1989) 168 CLR 210 at 216 per Mason CJ, Brennan, Dawson and Gaudron JJ, in turn quoting Water Conservation and Irrigation Commission (NSW) v Browning (1947) 74 CLR 492 at 505 per Dixon J.

20. Where s 34(2)(b)(ii) is engaged but, for whatever reason, it can be seen that the naturalised person was nonetheless of "good character" when he or she applied for citizenship, it will be open to a Minister, for the purposes of s 34(2)(c), to fail to be satisfied that it would be contrary to the public interest for the person to remain a citizen.

21. The third aspect is most troubling. It is at least an unattractive legislative choice to expose a citizen from the date of conviction until death to the risk of denationalisation – a risk which hangs over the head of such a person like the "sword of Damocles". It is harder to justify on this occasion a sufficient connection between such an open‑ended power and a non‑punitive purpose of protecting the integrity of the naturalisation process. Yet, care must be taken not to introduce here a requirement of legal reasonableness, if in substance that means that the law must be proportionate in order to be valid[224]. Asking whether a law is reasonably capable of being seen as necessary for a legitimate non-punitive purpose is to ask a question concerning that law's purpose. Here, the question must be: does the creation of such an open-ended power of denationalisation preclude the characterisation of s 34(2)(b)(ii) – and 34(2)(c) – as laws which exist for the purpose of protecting the integrity of the naturalisation process?

    [224]Falzon v Minister for Immigration and Border Protection (2018) 262 CLR 333 at 343-344 [25]-[32] per Kiefel CJ, Bell, Keane and Edelman JJ.

22. With some hesitation, and with very great respect, the answer must be "No". That is because the law still addresses the behaviour – or good character – of the naturalised person before the grant of citizenship. It is also because that person must be taken to have had notice of the future risk of revocation when they committed a serious crime prior to naturalisation. And, like the second aspect above, the Minister must still be satisfied that it would be contrary to the "public interest" for the person to remain an Australian citizen. In that respect, it should be accepted, at least in general terms, that the larger the time period between conviction and consideration of the power to denationalise, the more difficult it will be for the Minister to be so satisfied.

    Relief

1. I agree with the answers given by Kiefel CJ, Gageler, Gleeson and Jagot JJ to the questions posed by the special case.