R (Miller) v Secretary of State for Exiting the European Union

Hilary Term

[2017] UKSC 5

On appeals from: [2016] EWHC 2768 (Admin) and [2016] NIQB 85

R (on the application of Miller and another) (Respondents) v Secretary of State for Exiting the European Union (Appellant) REFERENCE by the Attorney General for Northern Ireland - In the matter of an application by Agnew and others for Judicial Review REFERENCE by the Court of Appeal (Northern Ireland) – In the matter of an application by Raymond McCord for Judicial Review

before

Lord Neuberger, President

Lord Hughes Lord Hodge

JUDGMENT GIVEN ON

24 January 2017

Heard on 5, 6, 7 and 8 December 2016

Appellant (Miller)	1st Respondent (Miller)
Jeremy Wright QC, HM	Lord Pannick QC
Attorney General	Rhodri Thompson QC
Lord Keen QC, Advocate	Anneli Howard
General for Scotland	Tom Hickman
James Eadie QC	Professor Dan Sarooshi
Jason Coppel QC

Guglielmo Verdirame

Tom Cross

Christopher Knight

(Instructed by The	(Instructed by Mishcon de
Government Legal	Reya LLP)

Department)

2nd Respondent (Dos

Santos)

Dominic Chambers QC

Jessica Simor QC

Benjamin John

(Instructed by Edwin Coe

LLP)

Attorney General for

Northern Ireland

John F Larkin QC,

Attorney General for

Northern Ireland

Conleth Bradley SC

(Instructed by Office of

the Attorney General for

Northern Ireland)

NI Reference (Agnew and

others)

David A Scoffield QC

Professor Christopher

McCrudden

Professor Gordon

Anthony

(Instructed by Jones

Cassidy Brett Solicitors)

NI Reference (SoS

Northern Ireland)

Tony McGleenan QC

Paul McLaughlin

(Instructed by Crown

Solicitor’s Office)

NI Reference (McCord)

Ronan Lavery QC

Conan Fegan BL

(Instructed by McIvor

Farrell Solicitors)

Ist Interested Party	2nd Interested Party (AB
(Pigney and others)	and others)
Helen Mountfield QC	Manjit Gill QC
Gerry Facenna QC	Ramby De Mello
Professor Robert	Tony Muman
McCorquodale	Stuart Luke
Tim Johnstone	Martin Bridger
David Gregory

Jack Williams

(Instructed by Bindmans

(Instructed by Bhatia Best)

LLP)

1st Intervener (Birnie and

2nd Intervener (Lord

others)

Advocate)

Patrick Green QC

James Wolffe QC, Lord

Advocate

Henry Warwick

Martin Chamberlain QC

Paul Skinner

Douglas Ross QC

Matthieu Gregoire	Duncan Hamilton
Christine O’Neill
Emily MacKenzie
(Instructed by Croft	(Instructed by Scottish

Solicitors)

Government Legal

Directorate)

3rd Intervener (Counsel	4th Intervener (TWGB)
General of Wales)	(Written submissions only)
Richard Gordon QC	Aidan O’Neill QC

Tom Pascoe

Peter Sellar

(Instructed by Welsh	(Instructed by Leigh Day)
Government Legal
Services Department)

5th Intervener (Lawyers of

Britain)

(Written submissions only)

Martin Howe QC

Thomas Sharpe QC

Simon Salzedo QC

Andrew Henshaw QC

Thomas Roe QC

James Bogle

Francis Hoar

Adam Richardson

(Instructed by Wedlake

Bell LLP)

LORD NEUBERGER: (with whom Lady Hale, Lord Mance, Lord Kerr,

Lord Clarke, Lord Wilson, Lord Sumption and Lord Hodge agree)

Introductory

1.         On 1 January 1973, the United Kingdom became a member of the European

Economic Community (“the EEC”) and certain other associated European

organisations. On that date, EEC law took effect as part of the domestic law of the United Kingdom, in accordance with the European Communities Act 1972 which had been passed ten weeks earlier. Over the next 40 years, the EEC expanded from

nine to 28 member states, extended its powers or “competences”, merged with the

associated organisations, and changed its name to the European Community in 1993
and to the European Union in 2009.

2. In December 2015, the UK Parliament passed the European Union Referendum Act, and the ensuing referendum on 23 June 2016 produced a majority in favour of leaving the European Union. UK government ministers (whom we will

call “ministers” or “the UK government”) thereafter announced that they would

bring UK membership of the European Union to an end. The question before this Court concerns the steps which are required as a matter of UK domestic law before the process of leaving the European Union can be initiated. The particular issue is whether a formal notice of withdrawal can lawfully be given by ministers without prior legislation passed in both Houses of Parliament and assented to by HM The Queen.

3. It is worth emphasising that nobody has suggested that this is an inappropriate issue for the courts to determine. It is also worth emphasising that this case has nothing to do with issues such as the wisdom of the decision to withdraw from the European Union, the terms of withdrawal, the timetable or arrangements for withdrawal, or the details of any future relationship with the European Union. Those are all political issues which are matters for ministers and Parliament to resolve. They are not issues which are appropriate for resolution by judges, whose duty is to decide issues of law which are brought before them by individuals and entities exercising their rights of access to the courts in a democratic society.

4. Some of the most important issues of law which judges have to decide concern questions relating to the constitutional arrangements of the United Kingdom. These proceedings raise such issues. As already indicated, this is not

because they concern the United Kingdom’s membership of the European Union; it

is because they concern (i) the extent of ministers’ power to effect changes in

domestic law through exercise of their prerogative powers at the international level, and (ii) the relationship between the UK government and Parliament on the one hand and the devolved legislatures and administrations of Scotland, Wales and Northern Ireland on the other.

5. The main issue on this appeal concerns the ability of ministers to bring about changes in domestic law by exercising their powers at the international level, and it

arises from two features of the United Kingdom’s constitutional arrangements. The

first is that ministers generally enjoy a power freely to enter into and to terminate treaties without recourse to Parliament. This prerogative power is said by the Secretary of State for Exiting the European Union to include the right to withdraw

from the treaties which govern UK membership of the European Union (“the EU

Treaties”). The second feature is that ministers are not normally entitled to exercise

any power they might otherwise have if it results in a change in UK domestic law, unless statute, ie an Act of Parliament, so provides. The argument against the Secretary of State is that this principle prevents ministers withdrawing from the EU Treaties, until effectively authorised to do so by a statute.

6. Most of the devolution issues arise from the contention that the terms on which powers have been statutorily devolved to the administrations of Scotland, Wales and Northern Ireland are such that, unless Parliament provides for such withdrawal by a statute, it would not be possible for formal notice of the United

Kingdom’s withdrawal from the EU Treaties to be given without first consulting or

obtaining the agreement of the devolved legislatures. And, in the case of Northern
Ireland, there are certain other arguments of a constitutional nature.

7. The main issue was raised in proceedings brought by Gina Miller and Deir dos Santos (“the applicants”) against the Secretary of State for Exiting the European

Union in the Divisional Court of England and Wales. Those proceedings came before Lord Thomas of Cwmgiedd LCJ, Sir Terence Etherton MR and Sales LJ. They ruled against the Secretary of State in a judgment given on 3 November 2016 - R (Miller) v The Secretary of State for Exiting the European Union [2016] EWHC 2768 (Admin). This decision now comes to this Court pursuant to an appeal by the Secretary of State.

8. The applicants are supported in their opposition to the appeal by a number of people, including (i) a group deriving rights of residence in the UK under EU law on the basis of their relationship with a British national or with a non-British EU national exercising EU Treaty rights to be in the United Kingdom, (ii) a group deriving rights of residence from persons permitted to reside in the UK because of EU rights, including children and carers, (iii) a group mostly of UK citizens residing elsewhere in the European Union, (iv) a group who are mostly non-UK EU nationals residing in the United Kingdom, and (v) the Independent Workers Union of Great

Britain. The Secretary of State’s case is supported by Lawyers for Britain Ltd, a

group of lawyers.

9. Devolution arguments relating to Northern Ireland were raised in proceedings brought by Steven Agnew and others and by Raymond McCord against the Secretary of State for Exiting the European Union and the Secretary of State for Northern Ireland. Those arguments were rejected by Maguire J in a judgment given in the Northern Ireland High Court on 28 October 2016 - Re McCord, Judicial Review [2016] NIQB 85. On application by the Attorney General for Northern Ireland, Maguire J referred four of the issues in the Agnew case to this court for

determination. Following an appeal against Maguire J’s decision, the Northern

Ireland Court of Appeal has also referred one issue to this Court.

10.       The Attorney General for Northern Ireland supports the Secretaries of State’s

case that no statute is required before ministers can give notice of withdrawal. In addition, there are interventions on devolution issues by the Lord Advocate on behalf of the Scottish government and the Counsel General for Wales on behalf of the Welsh government; they also rely on the Sewel Convention (as explained in paras 137 to 139 below). They support the argument that a statute is required before ministers can give notice of withdrawal, as do the advocates for Mr McCord and for Mr Agnew.

11. We are grateful to all the advocates and solicitors involved for the clarity and skill with which the respective cases have been presented orally and in writing, and for the efficiency with which the very substantial documentation was organised. We have also been much assisted by a number of illuminating articles written by academics following the handing down of the judgment of the Divisional Court. It is a tribute to those articles that they have resulted in the arguments advanced before this Court being somewhat different from, and more refined than, those before that court.

12. As mentioned in paras 7 and 9 above, the appellant in the English and Welsh appeal is the Secretary of State for Exiting the European Union, and the Northern Irish proceedings were brought against the Secretary of State for Exiting the European Union and the Secretary of State for Northern Ireland. For the sake of simplicity, we will hereafter refer to either or both Secretaries of State simply as

“the Secretary of State”.

The United Kingdom’s Relationship with the European Union 1971-2016

The relationship between the UK and the EU 1971-1975

13. From about 1960, the UK government was in negotiations with the then member states of the EEC with a view to the United Kingdom joining the EEC and associated European organisations. In October 1971, when it had become apparent that those negotiations were likely to be successful, and following debates in each

House, the House of Lords and the House of Commons each resolved to “approve

… Her Majesty’s Government’s decision of principle to join the European

Communities on the basis of the arrangements which have been negotiated”. In the

course of the debate in the House of Commons, the Prime Minister, Mr Heath, said

that he did not think that “any Prime Minister has … in time of peace … asked the

House to take a positive decision of such importance as I am asking it to take”, and that he could not “over-emphasise tonight the importance of the vote which is being

taken, the importance of the issue, the scale and quality of the decision and the

impact that it will have equally inside and outside Britain”. In a debate in the House

of Commons in January 1972, in which the earlier resolution was effectively re-

affirmed, Mr Rippon, the Chancellor of the Duchy of Lancaster, said “I do not think

Parliament in negotiations on a treaty has ever been brought so closely into the

process of treaty-making as on the present occasion”, adding that “we all accept the
unique character of the Treaty of Accession”.

14. On 22 January 1972, two days after that later debate, ministers signed a Treaty of Accession which provided that the United Kingdom would become a member of the EEC on 1 January 1973 and would accordingly be bound by the 1957 Treaty of Rome, which was then the main treaty in relation to the EEC, and by certain other connected treaties. As with most international treaties, the 1972 Accession Treaty was not binding unless and until it was formally ratified by the United Kingdom.

15. A Bill was then laid before Parliament, and after it had been passed by both Houses, it received Royal assent on 17 October 1972, when it became the European Communities Act 1972. The following day, 18 October 1972, ministers ratified the 1972 Accession Treaty on behalf of the United Kingdom, which accordingly became a member of the EEC on 1 January 1973.

16.       The long title of the 1972 Act described its purpose as “to make provision in

connection with the enlargement of the European Communities to include the

United Kingdom …”. Part I of the 1972 Act consisted of sections 1 to 3, which

contained its “General Provisions”, and they are of central importance to these

proceedings.

17. Section 1(2) of the 1972 Act contained some important definitions. “The Communities” meant the EEC and associated communities (now amended to “the

EU” meaning the European Union). And “the Treaties” and “the Community

Treaties” (now amended to “the EU Treaties”) were the treaties described in

Schedule 1 (which were the existing treaties governing the rules and powers of the

EEC at that time), the 1972 Accession Treaty itself, and “any other treaty entered

into by any of the Communities, with or without any of the member States, or

entered into, as a treaty ancillary to any of the Treaties, by the United Kingdom”.

The use of a capital T in “the Treaties” and in “the EU Treaties” was significant. It

meant that future treaties which were concerned with changing the membership or

redefining the rules of the EEC could only become “Treaties” and “EU Treaties”

and have effect in UK law as such if they were added to section 1(2) by an amending

statute. By contrast, “ancillary” treaties covered other treaties entered into by the

European Union or by the United Kingdom as a treaty ancillary to the EU Treaties. By virtue of section 1(3), even such an ancillary treaty did not take effect in UK law unless and until it was declared to do so by an Order in Council which had first to

be “approved” in draft form “by resolution of each House of Parliament”.

18.       Section 2 of the 1972 Act was headed “General Implementation of Treaties”.

Section 2(1) of the 1972 Act was in these terms:

“All such rights, powers, liabilities, obligations and restrictions

from time to time created or arising by or under the Treaties, and all such remedies and procedures from time to time provided for by or under the Treaties, as in accordance with the Treaties are without further enactment to be given legal effect or used in the United Kingdom shall be recognised and available in law, and be enforced, allowed and followed

accordingly …”

19.       Section 2(2) of the 1972 Act provided that “Her Majesty may by Order in

Council, and any designated Minister or department may by regulations, make

provision” (a) “for the purpose of implementing any Community [now EU]

obligation of the United Kingdom” (which is defined as any obligation “created or

arising by or under the Treaties”) or “enabling any rights … enjoyed … by the

United Kingdom under or by virtue of the Treaties to be exercised”, and (b) for

ancillary purposes, including “the operation from time to time of subsection (1)”.

Subsection (2) has since been amended, but nothing hangs on the amendments for

present purposes. Schedule 2 to the 1972 Act contained “Provisions as to

Subordinate Legislation” in relation to the powers conferred by section 2(2).

20.       Section 2(4) provided as follows:

“The provision that may be made under subsection (2) above

includes ... any such provision (of any such extent) as might be made by Act of Parliament, and any enactment passed or to be passed, other than one contained in this Part of this Act, shall be construed and have effect subject to the foregoing provisions

of this section …”

21. Section 3 of the 1972 Act provided, among other things, for any question as to the meaning and effect of the Treaties, or as to the validity, meaning or effect of

any “Community instrument” (now “EU instrument”) to be treated as a question of

EU law by the UK courts, and it further provided for such determination to be made

in accordance with principles laid down by the European Court of Justice (“the Court

of Justice”) or, if necessary, to be referred to the Court of Justice.

22. Part II of the 1972 Act, which contained sections 4 to 12, and incorporated Schedules 3 and 4, set out a number of statutory repeals and amendments which were needed to enable UK domestic law to comply with the requirements of EU law, that is the law from time to time laid down in the EU Treaties, Directives and Regulations, as interpreted by the Court of Justice.

23. Following a manifesto commitment made during a general election in 1974, the UK government decided to hold a referendum on whether the United Kingdom should remain in the EEC. To that end, it laid a Bill before Parliament which was duly enacted as the Referendum Act 1975. The referendum pursuant to that Act took place on 5 June 1975, and a majority of those who voted were in favour of remaining in the EEC.

The relationship between the UK and the EU after 1975

24. In the past 40 years, over 20 treaties relating to the EEC, the European Community and the European Union were signed on behalf of the member states, in the case of the United Kingdom by ministers. After being signed, each such treaty

was then added to the list of “Treaties” in section 1(2) of the 1972 Act through the

medium of an amendment made to that statute by a short appropriately worded statute passed by Parliament, and the treaty was then ratified by the United Kingdom. Some of these Treaties were concerned with redefining and expanding the competences of the EEC, the European Community and the European Union and changing the constitutional role of the European Parliament within the European Community or Union. They included the Single European Act signed in 1986, Titles

II, III and IV of the Maastricht Treaty on European Union of 7 February 1992 (“the

TEU”), the 1997 Amsterdam Treaty, the 2001 Treaty of Nice, and the Treaty of

Lisbon amending the TEU and the Treaty on the Functioning of the European Union
(“TFEU”), both signed in Lisbon on 13 December 2007 - see respectively section

1(2)(j), added by the European Communities (Amendment) Act 1986; section 1(2)(k), added by the European Communities (Amendment) Act 1993; section 1(2)(o), added by the European Communities (Amendment) Act 1998; section 1(2)(p), added by the European Communities (Amendment) Act 2002; and section 1(2)(s), added by the European Union (Amendment) Act 2008.

25. The Treaty of Lisbon introduced into the EU Treaties for the first time an express provision entitling a member state to withdraw from the European Union. It

did this by inserting a new article 50 into the TEU. This article (“article 50”)

provides as follows:

“1. Any member state may decide to withdraw from the Union in accordance with its own constitutional requirements.

2. A member state which decides to withdraw shall notify the European Council of its intention. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that state, setting out

the arrangements for its withdrawal …

3. The Treaties shall cease to apply to the state in question from the date of entry into force of the withdrawal agreement or, failing that, two years after the notification referred to in paragraph 2, unless the European Council, in agreement with the member state concerned, unanimously decides to extend

this period. …”

26.       In these proceedings, it is common ground that notice under article 50(2)

(which we shall call “Notice”) cannot be given in qualified or conditional terms and

that, once given, it cannot be withdrawn. Especially as it is the Secretary of State’s

case that, even if this common ground is mistaken, it would make no difference to the outcome of these proceedings, we are content to proceed on the basis that that is correct, without expressing any view of our own on either point. It follows from this that once the United Kingdom gives Notice, it will inevitably cease at a later date to be a member of the European Union and a party to the EU Treaties.

27. After 1975, in addition to the amending statutes referred to in para 24 above, statutes were enacted to give effect to changes in the way that members of the European Parliament were selected. The first was the European Assembly Elections Act 1978, which contained in section 6 a stipulation that no new treaty providing for an increase in the powers of the European Assembly (as it then was) should be ratified unless approved by an Act of Parliament. This provision was re-enacted as section 12 of the European Parliamentary Elections Act 2002. Section 1 of the 2002 Act provided for a specific number of Members of the European Parliament

(“MEPs”) for specified regions of the United Kingdom. Section 8 of the 2002 Act

stated that a person was entitled to vote in elections to the European Parliament if he or she satisfied certain residence requirements, and section 10 identified the (very limited) categories of people who were disqualified from standing as MEPs.

28. In addition to adding the Treaty of Lisbon and the TFEU to section 1(2) of the 1972 Act, the 2008 Act, referred to at the end of para 24 above, contained certain

restrictions on the UK government’s agreement to changes in the rules of the

European Union. Section 5 provided that any treaty which amended the TEU or the TFEU by altering the competences of the European Union, or which altered the decision-making processes of the European Union or its institutions in such a way as to dilute the influence of individual member states, should not be ratified by

ministers “unless approved by Act of Parliament”. Section 6 of the 2008 Act stated

that ministers should not support any decision under certain specified articles of the TEU and of the TFEU unless both Houses of Parliament had approved a motion sanctioning that course.

29. Subject to an immaterial exception, the European Union Act 2011 repealed and replaced sections 5 and 6 of the 2008 Act. Part I of the 2011 Act included section

1 which was “Introductory”, sections 2 to 10, which imposed “Restrictions” both

“relating to amendments of TEU and TFEU” and “relating to other decisions under

TEU and TFEU”, and sections 11 to 13, which related to the conduct of referendums.

Sections 2 to 5 imposed restrictions on the ratification by the United Kingdom of any treaty which amended or replaced TEU or TFEU, and also on ministers approving certain specified types of EU decisions under the so-called simplified revision procedure. Those restrictions were that (a) a statement relating to the treaty or decision had to be laid before Parliament, (b) the treaty or decision had to be approved by statute, and, (c) in broad terms, where the treaty or decision increased the competences of the European Union, it had to be approved in a UK-wide referendum. Section 6 provided that ministers should not, without prior approval both in a statute and in a UK-wide referendum, vote in favour of certain decisions, including those which resulted in a dilution in the influence of individual member states in relation to a number of different articles of the TEU and TFEU including in particular article 50(3). Sections 7 to 10 of the 2011 Act contained further restrictions on ministers voting in favour of certain measures under the TEU and TFEU without the prior approval of Parliament.

30.       Section 18 of the 2011 Act provided as follows:

“Directly applicable or directly effective EU law (that is, the

rights, powers, liabilities, obligations, restrictions, remedies and procedures referred to in section 2(1) of the European Communities Act 1972) falls to be recognised and available in law in the United Kingdom only by virtue of that Act or where it is required to be recognised and available in law by virtue of

any other Act.”

31. Following a manifesto commitment in the 2015 general election to hold a referendum on the issue of EU membership, the UK government laid before

Parliament a Bill which became the 2015 Act. Section 1 provided that “[a]

referendum is to be held” on a date no later than 31 December 2017 “on whether the

United Kingdom should remain a member of the European Union”, and it specified

the question which should appear on the ballot papers. The remaining sections were concerned with questions such as entitlement to vote, the conduct of the referendum, rules about campaigning and financial controls.

32. The referendum duly took place throughout the United Kingdom on 23 June 2016, and it resulted in a majority in favour of leaving the European Union. Ministers have made it clear that the UK government intends to implement the result of the referendum and to give Notice by the end of March 2017.

33.       On 7 December 2016, following a debate, the House of Commons resolved

“[to recognise] … that this House should respect the wishes of the United Kingdom

as expressed in the referendum on 23 June; and further [to call] on the Government

to invoke article 50 by 31 March 2017”.

The main issue: the 1972 Act and prerogative powers

Summary of the arguments on the main issue

34. The Secretary of State’s case is based on the existence of the well-established prerogative powers of the Crown to enter into and to withdraw from treaties. He contends that ministers are entitled to exercise this power in relation to the EU Treaties, and therefore to give Notice without the need for any prior legislation. Following the giving of Notice by the end of March 2017, ministers intend that a

“Great Repeal Bill” will be laid before Parliament. This will repeal the 1972 Act

and, wherever practical, it will convert existing EU law into domestic law at least for a transitional period. Under article 50, withdrawal will occur not more than two years after the Notice is given (unless that period is extended by unanimous agreement among the other member states), and it is intended that the Great Repeal Bill will come into force at that point.

35. As was made clear by Lord Browne-Wilkinson in R v Secretary of State for the Home Department, Ex p Fire Brigades Union [1995] 2 AC 513, 552, ministers’

intentions are not law, and the courts cannot proceed on the assumption that they will necessarily become law. That is a matter for Parliament to decide in due course. The issues before us must be resolved in accordance with the law as it stands, as the Secretary of State rightly accepted.

36.       The applicants’ case in that connection is that when Notice is given, the

United Kingdom will have embarked on an irreversible course that will lead to much of EU law ceasing to have effect in the United Kingdom, whether or not Parliament repeals the 1972 Act. As Lord Pannick QC put it for Mrs Miller, when ministers

give Notice they will be “pulling … the trigger which causes the bullet to be fired,

with the consequence that the bullet will hit the target and the Treaties will cease to

apply”. In particular, he said, some of the legal rights which the applicants enjoy

under EU law will come to an end. This, he submitted, means that the giving of Notice would pre-empt the decision of Parliament on the Great Repeal Bill. It would be tantamount to altering the law by ministerial action, or executive decision, without prior legislation, and that would not be in accordance with our law.

37. Following opening remarks made by HM Attorney General, Mr Eadie QC in his submissions on behalf of the Secretary of State, did not challenge much if any of the factual basis of these assertions, but he did challenge the conclusions that were said to derive from them. He argued that the fact that significant legal changes will follow from withdrawing from the EU Treaties does not prevent the giving of Notice, because the prerogative power to withdraw from treaties was not excluded

by the terms of the 1972 Act, and that, in any event, “acts of the government in the

exercise of the prerogative can alter domestic law”. More particularly, he contended

that the 1972 Act gave effect to EU law only insofar as the EU Treaties required it, and that that effect was therefore contingent upon the United Kingdom remaining a party to those treaties. Accordingly, he said, in the 1972 Act Parliament had effectively stipulated that, or had sanctioned the result whereby, EU law should cease to have domestic effect in the event that minsters decided to withdraw from the EU Treaties.

38. Mr Eadie also relied on the fact that, while statutes enacted since 1972 have imposed Parliamentary controls over the exercise of prerogative powers in relation to the EU Treaties, they have not touched the prerogative power to withdraw from them. Implicitly, therefore, he contended, Parliament has recognised that the power to withdraw from such treaties exists and is exercisable without prior legislation. Mr Eadie also suggested that the 2015 Act was enacted on the assumption that the result

of the referendum would be decisive. Mr Eadie’s reliance on the legislation since

1972 was largely for the purpose of supporting his argument on the effect of the 1972 Act, but he did raise an argument that the legislation from 1972 to 2015 should be looked at as a whole. Also, in answer to a question from the Court, he adopted a suggestion that, even if Parliamentary authority would otherwise have been required, the 2015 Act and the subsequent referendum dispensed with that requirement, but he did not develop that argument, in our view realistically.

39. Before addressing these arguments, it is right to consider some relevant constitutional principles and in particular the Royal prerogative.

The constitutional background

40. Unlike most countries, the United Kingdom does not have a constitution in the sense of a single coherent code of fundamental law which prevails over all other sources of law. Our constitutional arrangements have developed over time in a pragmatic as much as in a principled way, through a combination of statutes, events, conventions, academic writings and judicial decisions. Reflecting its development and its contents, the UK constitution was described by the constitutional scholar, Professor AV Dicey, as “the most flexible polity in existence” - Introduction to the

Study of the Law of the Constitution (8th ed, 1915), p 87.

41. Originally, sovereignty was concentrated in the Crown, subject to limitations which were ill-defined and which changed with practical exigencies. Accordingly, the Crown largely exercised all the powers of the state (although it appears that even in the 11th century the King rarely attended meetings of his Council, albeit that its membership was at his discretion). However, over the centuries, those prerogative powers, collectively known as the Royal prerogative, were progressively reduced as Parliamentary democracy and the rule of law developed. By the end of the 20th century, the great majority of what had previously been prerogative powers, at least in relation to domestic matters, had become vested in the three principal organs of the state, the legislature (the two Houses of Parliament), the executive (ministers and the government more generally) and the judiciary (the judges). It is possible to identify a number of seminal events in this history, but a series of statutes enacted in the twenty years between 1688 and 1707 were of particular legal importance. Those statutes were the Bill of Rights 1688/9 and the Act of Settlement 1701 in England and Wales, the Claim of Right 1689 in Scotland, and the Acts of Union 1706 and 1707 in England and Wales and in Scotland respectively. (Northern Ireland joined the United Kingdom pursuant to the Acts of Union 1800 in Britain and Ireland).

42. The independence of the judiciary was formally recognised in these statutes. In the broadest sense, the role of the judiciary is to uphold and further the rule of law; more particularly, judges impartially identify and apply the law in every case brought before the courts. That is why and how these proceedings are being decided. The law is made in or under statutes, but there are areas where the law has long been laid down and developed by judges themselves: that is the common law. However, it is not open to judges to apply or develop the common law in a way which is inconsistent with the law as laid down in or under statutes, ie by Acts of Parliament.

43. This is because Parliamentary sovereignty is a fundamental principle of the UK constitution, as was conclusively established in the statutes referred to in para 41 above. It was famously summarised by Professor Dicey as meaning that

Parliament has “the right to make or unmake any law whatsoever; and further, no

person or body is recognised by the law as having a right to override or set aside the legislation of Parliament; and, further, that no person or body is recognised by the law of England as having a right to override or set aside the legislation of Parliament” - op cit, p 38. The legislative power of the Crown is today exercisable

only through Parliament. This power is initiated by the laying of a Bill containing a proposed law before Parliament, and the Bill can only become a statute if it is passed (often with amendments) by Parliament (which normally but not always means both Houses of Parliament) and is then formally assented to by HM The Queen. Thus, Parliament, or more precisely the Crown in Parliament, lays down the law through statutes - or primary legislation as it is also known - and not in any other way.

44. In the early 17th century Case of Proclamations (1610) 12 Co Rep 74, Sir Edward Coke CJ said that “the King by his proclamation or other ways cannot change any part of the common law, or statute law, or the customs of the realm”.

Although this statement may have been controversial at the time, it had become firmly established by the end of that century. In England and Wales, the Bill of

Rights 1688 confirmed that “the pretended power of suspending of laws or the execution of laws by regall authority without consent of Parlyament is illegall” and

that “the pretended power of dispensing with laws or the execution of laws by regall

authoritie as it hath beene assumed and exercised of late is illegall”. In Scotland, the

Claim of Right 1689 was to the same effect, providing that “all Proclamationes

asserting ane absolute power to Cass [ie to quash] annull and Dissable lawes … are Contrair to Law”. And article 18 of the Acts of Union of 1706 and 1707 provided

that (with certain irrelevant exceptions) “all … laws” in Scotland should “remain in

the same force as before … but alterable by the Parliament of Great Britain”.

45. The Crown’s administrative powers are now exercised by the executive, ie by ministers who are answerable to the UK Parliament. However, consistently with the principles established in the 17th century, the exercise of those powers must be compatible with legislation and the common law. Otherwise, ministers would be changing (or infringing) the law, which, as just explained, they cannot do. A classic statement of the position was given by Lord Parker of Waddington in The Zamora [1916] 2 AC 77, 90:

“The idea that the King in Council, or indeed any branch of the

Executive, has power to prescribe or alter the law to be administered by Courts of law in this country is out of harmony with the principles of our Constitution. It is true that, under a number of modern statutes, various branches of the Executive have power to make rules having the force of statutes, but all such rules derive their validity from the statute which creates the power, and not from the executive body by which they are made. No one would contend that the prerogative involves any power to prescribe or alter the law administered in Courts of

Common Law or Equity.”

46. It is true that ministers can make laws by issuing regulations and the like, often known as secondary or delegated legislation, but (save in limited areas where a prerogative power survives domestically, as exemplified by the cases mentioned in paras 52 and 53 below) they can do so only if authorised by statute. So, if the regulations are not so authorised, they will be invalid, even if they have been approved by resolutions of both Houses under the provisions of the relevant enabling Act - for a recent example see R (The Public Law Project) v Lord Chancellor [2016] AC 1531.

The Royal prerogative and Treaties

47. The Royal prerogative encompasses the residue of powers which remain vested in the Crown, and they are exercisable by ministers, provided that the exercise is consistent with Parliamentary legislation. In Burmah Oil Co (Burma Trading) Ltd v Lord Advocate [1965] AC 75, 101, Lord Reid explained that the Royal prerogative

is a source of power which is “only available for a case not covered by statute”.

Professor HWR Wade summarised the position in his introduction to the first edition of what is now Wade and Forsyth on Administrative Law (1961), p 13:

“[T]he residual prerogative is now confined to such matters as

summoning and dissolving Parliament, declaring war and peace, regulating the armed forces in some respects, governing certain colonial territories, making treaties (though as such they cannot affect the rights of subjects), and conferring honours. The one drastic internal power of an administrative kind is the

power to intern enemy aliens in time of war.”

48. Thus, consistently with Parliamentary sovereignty, a prerogative power however well-established may be curtailed or abrogated by statute. Indeed, as Professor Wade explained, most of the powers which made up the Royal prerogative have been curtailed or abrogated in this way. The statutory curtailment or abrogation may be by express words or, as has been more common, by necessary implication. It is inherent in its residual nature that a prerogative power will be displaced in a field which becomes occupied by a corresponding power conferred or regulated by statute. This is what happened in the two leading 20th century cases on the topic,

Attorney General v De Keyser’s Royal Hotel Ltd [1920] AC 508 and Fire Brigades

Union cited above. As Lord Parmoor explained in De Keyser at p 575, when

discussing the prerogative power to take a subject’s property in time of war:

“The constitutional principle is that when the power of the Executive

to interfere with the property or liberty of subjects has been placed under Parliamentary control, and directly regulated by statute, the Executive no longer derives its authority from the Royal Prerogative of the Crown but from Parliament, and that in exercising such authority the Executive is bound to observe the restrictions which

Parliament has imposed in favour of the subject.”

49. In Burmah Oil cited above, at p 101, Lord Reid described prerogative powers as a “relic of a past age”, but that description should not be understood as implying

that the Royal prerogative is either anomalous or anachronistic. There are important areas of governmental activity which, today as in the past, are essential to the effective operation of the state and which are not covered, or at least not completely covered, by statute. Some of them, such as the conduct of diplomacy and war, are by their very nature at least normally best reserved to ministers just as much in modern times as in the past, as indeed Lord Reid himself recognised in Burmah Oil at p 100.

50. Consistently with paras 44 to 46, and the passage quoted from Professor Wade in para 47 above, it is a fundamental principle of the UK constitution that, unless primary legislation permits it, the Royal prerogative does not enable ministers to change statute law or common law. As Lord Hoffmann observed in R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs (No 2) [2009] AC 453,

para 44, “since the 17th century the prerogative has not empowered the Crown to

change English common or statute law”. This is, of course, just as true in relation to Scottish, Welsh or Northern Irish law. Exercise of ministers’ prerogative powers

must therefore be consistent both with the common law as laid down by the courts
and with statutes as enacted by Parliament.

51. Further, ministers cannot frustrate the purpose of a statute or a statutory provision, for example by emptying it of content or preventing its effectual operation. Thus, ministers could not exercise prerogative powers at the international level to revoke the designation of Laker Airways under an aviation treaty as that would have rendered a licence granted under a statute useless: Laker Airways Ltd v Department of Trade [1977] QB 643 - see especially at pp 718-719 and 728 per Roskill LJ and Lawton LJ respectively. And in Fire Brigades Union cited above, at pp 551-552, Lord Browne-Wilkinson concluded that ministers could not exercise the prerogative power to set up a scheme of compensation for criminal injuries in such a way as to make a statutory scheme redundant, even though the statute in question was not yet in force. And, as already mentioned in para 35 above, he also stated that it was inappropriate for ministers to base their actions (or to invite the court to make any decision) on the basis of an anticipated repeal of a statutory

provision as that would involve ministers (or the court) pre-empting Parliament’s

decision whether to enact that repeal.

52. The fact that the exercise of prerogative powers cannot change the domestic law does not mean that such an exercise is always devoid of domestic legal consequences. There are two categories of case where exercise of the prerogative can have such consequences. The first is where it is inherent in the prerogative power that its exercise will affect the legal rights or duties of others. Thus, the Crown has a prerogative power to decide on the terms of service of its servants, and it is inherent in that power that the Crown can alter those terms so as to remove rights, albeit that such a power is susceptible to judicial review: Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374. The Crown also has a prerogative power to destroy property in wartime in the interests of national defence (although at common law compensation was payable: Burmah Oil cited above). While the exercise of the prerogative power in such cases may affect individual rights, the important point is that it does not change the law, because the law has always authorised the exercise of the power.

53. The second category comprises cases where the effect of an exercise of prerogative powers is to change the facts to which the law applies. Thus, the exercise of the prerogative to declare war will have significant legal consequences: actions which were previously lawful may become treasonable (as in Joyce v Director of Public Prosecutions [1946] AC 347), and some people will become enemy aliens, whose property is liable to confiscation. Likewise, in Post Office v Estuary Radio

Ltd [1968] 2 QB 740 the Crown’s exercise of its prerogative to extend UK territorial

waters resulted in the criminalisation of broadcasts from ships in the extended area, which had previously been lawful. These are examples where the exercise of the prerogative power alters the status of a person, thing or activity so that an existing rule of law comes to apply to it. However, in such cases the exercise has not created or changed the law, merely the extent of its application.

54.       The most significant area in which ministers exercise the Royal prerogative

is the conduct of the United Kingdom’s foreign affairs. This includes diplomatic

relations, the deployment of armed forces abroad, and, particularly in point for present purposes, the making of treaties. There is little case law on the power to terminate or withdraw from treaties, but, as a matter of both logic and practical necessity, it must be part of the treaty-making prerogative. As Lord Templeman put it in JH Rayner (Mincing Lane) Ltd v Department of Trade and Industry [1990] 2

AC 418, 476, “[t]he Government may negotiate, conclude, construe, observe,

breach, repudiate or terminate a treaty”.

55. Subject to any restrictions imposed by primary legislation, the general rule is that the power to make or unmake treaties is exercisable without legislative authority and that the exercise of that power is not reviewable by the courts - see Civil Service Unions case cited above, at pp 397-398. Lord Coleridge CJ said that the Queen acts

“throughout the making of the treaty and in relation to each and every of its

stipulations in her sovereign character, and by her own inherent authority” -

Rustomjee v The Queen (1876) 2 QBD 69, 74. This principle rests on the so-called dualist theory, which is based on the proposition that international law and domestic law operate in independent spheres. The prerogative power to make treaties depends on two related propositions. The first is that treaties between sovereign states have effect in international law and are not governed by the domestic law of any state. As Lord Kingsdown expressed it in Secretary of State in Council of India v Kamachee

Boye Sahaba (1859) 13 Moo PCC 22, 75, treaties are “governed by other laws than those which municipal courts administer”. The second proposition is that, although

they are binding on the United Kingdom in international law, treaties are not part of
UK law and give rise to no legal rights or obligations in domestic law.

56. It is only on the basis of these two propositions that the exercise of the prerogative power to make and unmake treaties is consistent with the rule that ministers cannot alter UK domestic law. Thus, in Higgs v Minister of National Security [2000] 2 AC 228, 241, Lord Hoffmann pointed out that the fact that treaties

are not part of domestic law was the “corollary” of the Crown’s treaty-making

power. In JH Rayner cited above, at p 500, Lord Oliver of Aylmerton put it thus:

“As a matter of the constitutional law of the United Kingdom,

the Royal Prerogative, whilst it embraces the making of treaties, does not extend to altering the law or conferring rights upon individuals or depriving individuals of rights which they enjoy in domestic law without the intervention of Parliament. Treaties, as it is sometimes expressed, are not self-executing. Quite simply, a treaty is not part of English law unless and until it has been incorporated into the law by legislation. So far as individuals are concerned, it is res inter alios acta [ie something done between others], from which they cannot derive rights and by which they cannot be deprived of rights or subjected to obligations; and it is outside the purview of the court not only because it is made in the conduct of foreign relations, which are a prerogative of the Crown, but also because, as a source of

rights and obligations, it is irrelevant.”

57. It can thus fairly be said that the dualist system is a necessary corollary of Parliamentary sovereignty, or, to put the point another way, it exists to protect Parliament not ministers. Professor Campbell McClachlan in Foreign Relations Law (2014), para 5.20, neatly summarises the position in the following way:

“If treaties have no effect within domestic law, Parliament’s

legislative supremacy within its own polity is secure. If the executive must always seek the sanction of Parliament in the event that a proposed action on the international plane will require domestic implementation, parliamentary sovereignty is reinforced at the very point at which the legislative power is

engaged.”

58. While ministers have in principle an unfettered power to make treaties which do not change domestic law, it had become fairly standard practice by the late 19th century for treaties to be laid before both Houses of Parliament at least 21 days before they were ratified, to enable Parliamentary objections to be heard. In 1924, following an indication by the previous government that it did not regard itself as bound by the practice, Arthur Ponsonby, the Parliamentary Under-Secretary of State for Foreign Affairs, assured the House of Commons that ministers would in future adhere to this practice, which became known as the Ponsonby Convention. The convention was superseded and formalised by section 20 of the Constitutional Reform and Governance Act 2010. However, by virtue of section 23(1) of that Act, this section does not apply to new EU Treaties, because they are governed by the more specific statutory controls discussed in paras 28 and 29 above.

59. With that background, we turn to analyse the effect of the 1972 Act and the arguments as to whether, in the absence of prior authority from Parliament in the form of a statute, the giving of Notice by ministers would be ineffective under the

United Kingdom’s constitutional requirements, as it would otherwise impermissibly

result in a change in domestic law.

The status and character of the 1972 Act

60. Many statutes give effect to treaties by prescribing the content of domestic law in the areas covered by them. The 1972 Act does this, but it does considerably more as well. It authorises a dynamic process by which, without further primary legislation (and, in some cases, even without any domestic legislation), EU law not only becomes a source of UK law, but actually takes precedence over all domestic sources of UK law, including statutes. This may sound rather dry or technical to many people, but in constitutional terms the effect of the 1972 Act was unprecedented. Indeed, it is fair to say that the legal consequences of the United

Kingdom’s accession to the EEC were not fully appreciated by many lawyers until

the Factortame litigation in the 1990s - see the House of Lords decisions in R v Secretary of State for Transport, Ex p Factortame Ltd (No 2) [1991] 1 AC 603 and (No 5) [2000] 1 AC 524. Of course, consistently with the principle of Parliamentary sovereignty, this unprecedented state of affairs will only last so long as Parliament wishes: the 1972 Act can be repealed like any other statute. For that reason, we would not accept that the so-called fundamental rule of recognition (ie the fundamental rule by reference to which all other rules are validated) underlying UK laws has been varied by the 1972 Act or would be varied by its repeal.

61. In one sense, of course, it can be said that the 1972 Act is the source of EU law, in that, without that Act, EU law would have no domestic status. But in a more fundamental sense and, we consider, a more realistic sense, where EU law applies in the United Kingdom, it is the EU institutions which are the relevant source of that law. The legislative institutions of the EU can create or abrogate rules of law which will then apply domestically, without the specific sanction of any UK institution. It is true that the UK government and UK-elected members of the European Parliament participate in the EU legislative processes and can influence their outcome, but that does not diminish the point. Further, in the many areas of EU competence which are subject to majority decision, the approval of the United Kingdom is not required for its legislation to take effect domestically. It is also true that EU law enjoys its automatic and overriding effect only by virtue of the 1972 Act, and thus only while it remains in force. That point simply reflects the fact that Parliament was and remains sovereign: so, no new source of law could come into existence without Parliamentary sanction - and without being susceptible to being abrogated by Parliament. However, that in no way undermines our view that it is unrealistic to deny that, so long as that Act remains in force, the EU Treaties, EU legislation and the interpretations placed on these instruments by the Court of Justice are direct sources of UK law.

62. The 1972 Act did two things which are relevant to these appeals. First, it provided that rights, duties and rules derived from EU law should apply in the United Kingdom as part of its domestic law. Secondly, it provided for a new constitutional process for making law in the United Kingdom. These things are closely related, but they are legally and conceptually distinct. The content of the rights, duties and rules introduced into our domestic law as a result of the 1972 Act is exclusively a question of EU law. However, the constitutional processes by which the law of the United Kingdom is made is exclusively a question of domestic law.

63. Under the terms of the 1972 Act, EU law may take effect as part of the law of the United Kingdom in one of three ways. First, the EU Treaties themselves are directly applicable by virtue of section 2(1). Some of the provisions of those Treaties create rights (and duties) which are directly applicable in the sense that they are enforceable in UK courts. Secondly, where the effect of the EU Treaties is that EU legislation is directly applicable in domestic law, section 2(1) provides that it is to have direct effect in the United Kingdom without the need for further domestic legislation. This applies to EU Regulations (which are directly applicable by virtue of article 288 of the TFEU). Thirdly, section 2(2) authorises the implementation of EU law by delegated legislation. This applies mainly to EU Directives, which are not, in general, directly applicable but are required (again by article 288) to be transposed into national law. While this is an international law obligation, failure of the United Kingdom to comply with it is justiciable in domestic courts, and some Directives may be enforced by individuals directly against national governments in domestic courts. Further, any serious breach by the UK Parliament, government or judiciary of any rule of EU law intended to confer individual rights will entitle any individual sustaining damage as a direct result to compensation from the UK government: Brasserie du Pêcheur SA v Germany; R v Secretary of State for Transport (Ex p Factortame Ltd) (No 4) (Joined Cases C-46/93 and C-48/93) [1996] QB 404 (provided that, where the breach consists in a court decision, the breach is not only serious but also manifest: Köbler v Austria (Case C-224/01) [2004] QB 848).

64. Thus, EU law in EU Treaties and EU legislation will pass into UK law through the medium of section 2(1) or the implementation provisions of section 2(2) of the 1972 Act, so long as the United Kingdom is party to the EU Treaties. Similarly, so long as the United Kingdom is party to the EU Treaties, UK courts are obliged (i) to interpret EU Treaties, Regulations and Directives in accordance with decisions of the Court of Justice, (ii) to refer unclear points of EU law to the Court of Justice, and (iii) to interpret all domestic legislation, if at all possible, so as to comply with EU law (see Marleasing v La Comercial Internacional de Alimentacion SA (Case C-106/89) [1990] ECR I-4135). And, so long as the United Kingdom is party to the EU Treaties, UK citizens are able to recover damages from the UK government in cases where a decision of one of the organs of the state based on a serious error of EU law has caused them loss.

65. In our view, then, although the 1972 Act gives effect to EU law, it is not itself the originating source of that law. It is, as was said on behalf of the Secretary of

State echoing the illuminating analysis of Professor Finnis, the “conduit pipe” by

which EU law is introduced into UK domestic law. So long as the 1972 Act remains in force, its effect is to constitute EU law an independent and overriding source of domestic law.

66. Section 18 of the 2011 Act, set out in para 30 above, was enacted in order to make it clear that the primacy of EU law over domestic legislation did not prevent it being repealed by domestic legislation. But that simply confirmed the position as it had been since the beginning of 1973. The primacy of EU law means that, unlike other rules of domestic law, EU law cannot be implicitly displaced by the mere enactment of legislation which is inconsistent with it. That is clear from the second part of section 2(4) of the 1972 Act and Factortame Ltd (No 2) [1991] 1 AC 603. The issue was informatively discussed by Laws LJ in Thoburn v Sunderland City Council [2003] QB 151, paras 37-47.

67. The 1972 Act accordingly has a constitutional character, as discussed by Laws LJ in Thoburn cited above, paras 58-59, and by Lord Reed and Lords Neuberger and Mance in in R (Buckinghamshire County Council) v Secretary of State for Transport [2014] 1 WLR 324, paras 78 to 79 and 206 to 207 respectively. Following the coming into force of the 1972 Act, the normal rule is that any domestic legislation must be consistent with EU law. In such cases, EU law has primacy as a matter of domestic law, and legislation which is inconsistent with EU law from time to time is to that extent ineffective in law. However, legislation which alters the domestic constitutional status of EU institutions or of EU law is not constrained by the need to be consistent with EU law. In the case of such legislation, there is no question of EU law having primacy, so that such legislation will have domestic effect even if it infringes EU law (and that would be true whether or not the 1972 Act remained in force). That is because of the principle of Parliamentary

sovereignty which is, as explained above, fundamental to the United Kingdom’s

constitutional arrangements, and EU law can only enjoy a status in domestic law which that principle allows. It will therefore have that status only for as long as the 1972 Act continues to apply, and that, of course, can only be a matter for Parliament.

68. We should add that, for these reasons, we do not accept the suggestion that, as a source of law, EU law can properly be compared with, delegated legislation. The 1972 Act effectively operates as a partial transfer of law-making powers, or an assignment of legislative competences, by Parliament to the EU law-making institutions (so long as Parliament wills it), rather than a statutory delegation of the power to make ancillary regulations - even under a so-called Henry the Eighth clause, as explained in the Public Law Project case, cited above, paras 25 and 26. The 1972 Act cannot be said to constitute EU legislative institutions the delegates of Parliament: they make laws independently of Parliament, and indeed they were doing so before the 1972 Act was passed. If EU law had the same status in domestic law as delegated legislation, the Factortame litigation referred to above would have had a different outcome. A statutory provision which provides that legislative documents and decisions made by EU institutions should be an independent and pre- eminent source of UK law is thus quite different from a statutory provision which delegates to ministers and other organs of the executive the right to make regulations and the like. The exceptional nature of the effect of the 1972 Act is well illustrated by the passages quoted by Lord Reed in para 182 below from the decisions of the Court of Justice in Van Gend en Loos (Case C-26/62) [1963] ECR 1, 12 and Costa v ENEL (Case C-6/64) [1964] ECR 585, 593. They demonstrate that rules which would, as Lord Reed says, normally be incompatible with UK constitutional principles, became part of our constitutional arrangements as a result of the 1972 Act and the 1972 Accession Treaty for as long as the 1972 Act remains in force.

by Parliament”. We were shown no authority to support a rule as so stated, nor any

principled basis for the court to invent it. In any event, that process, like the service of the article 50 notice, will be subject to Parliamentary scrutiny in whatever way Parliament chooses. It will be for Parliament and the Executive acting in partnership to determine the timing and content of the legislative programme.

Pre-empting the will of Parliament

265.     One possible answer to the analysis in the previous paragraph is that it would

involve the Executive unlawfully “frustrating” or “pre-empting” the will of

Parliament. This point is touched on in the majority judgment by reference in

particular to the Lord Browne-Wilkinson’s statements in the FBU case (see para 250 above). They are said to establish the principle that ministers cannot “frustrate” the

purpose of a statute “for example by emptying it of content or preventing its

effectual operation”; and that it is -

“… inappropriate for ministers to base their actions (or to invite

the court to make any decision) on the basis of an anticipated repeal of a statutory provision as that would involve ministers

(or the court) pre-empting Parliament’s decision whether to
enact that repeal.” (majority judgment para 51)

266. As I understand the majority judgment, however, this line of argument does not ultimately form part of their reasoning, in my view rightly so. In the first place, the FBU case was case about abuse, not absence, of power. There was no doubt as to the existence of the prerogative power. But it was held to be an abuse to use it for a purpose inconsistent with the will of Parliament, as expressed in a statute which had it had neither repealed nor been invited to repeal. Such issues do not arise in this case. The Miller respondents base their case unequivocally on absence of a prerogative power to nullify the statutory scheme set up by the 1972 Act, rather than

abuse (see Lord Pannick’s response to Lord Reed: Day 2 Transcript, p 158, lines 8-

25).

267. Further, Lord Browne-Wilkinson was not purporting to lay down any general principle about the relevance of future legislation in relation to the exercise of the prerogative. His comments were directed to the facts of the particular case, in which the new scheme was being introduced without any reference at all to Parliament. Similar arguments in the present case would have to be seen in a quite different context, which (as Lord Pannick accepts) would include the 2015 Act and the referendum result. It is one thing, as in the FBU case, to use the prerogative to introduce a scheme which is directly contrary to an extant Act, and which Parliament has had no chance consider. It is quite another to use it to give effect to a decision the manner of which has been determined by Parliament itself, and in the implementation of which Parliament will play a central role. In such circumstances talk of frustrating or pre-empting the will of Parliament would be wide of the mark. Conversely, it would be wrong to assume (as the majority appears to do: para 91) that the courts would necessarily have been powerless in the (politically inconceivable) event of the Executive initiating withdrawal entirely of its own motion, or even in defiance of a referendum vote to remain.

Protection of individual interests

268. I would not wish to leave the case without acknowledging the important submissions made by the other respondents and interveners, particularly as to the scale and significance of the interests which will be affected by withdrawal. It is not clear, however, how a requirement for statutory authority for the article 50(2) notice will do anything to safeguard those interests, nor indeed to advance the process of Parliamentary scrutiny which will ultimately be critical to their protection.

269. I take as representative the cases for the third and fourth respondents, presented by Ms Mountfield QC and Mr Gill QC. Their submissions provide vivid illustrations of the variety of ways in which individual and group interests will be profoundly affected by implementation of the decision to leave the EU. Ms

Mountfield for example provides a detailed breakdown of “fundamental” and “non-

replicable” EU citizenship rights. The list starts with the “fundamental status” of EU

citizenship (Citizens’ Directive 2004/38/EC preamble), leading to more specific

rights, such as the right to move, reside, work and study throughout the member states, the right to vote in European elections, the rights to diplomatic protection, and the right to equal pay, and to non-discriminatory healthcare free at the point of

use. She categorises the government’s case as an assertion of -

“untrammelled prerogative power to do away with the entire corpus

of European law rights currently enjoyed under UK law, and render a whole suite of constitutional statutes meaningless, without any

Parliamentary authority in the form of a statute.”

While there is no reason to question her account of the profound effect of the prospective changes, I do not for the reasons already given accept that this can be

describe as “untrammelled” use of executive power, nor that the control of

Parliament will be improperly bypassed. Nor does she explain how that impact will be mitigated by a statute which does no more than authorise service of the notice.

270. Similar arguments are made by Mr Gill for the fourth respondents (the AB parties). They are representative, among others, of the very large numbers of EEA nationals and their children living in this country, whose rights to continued residence will be threatened unless adequate arrangements are made to protect them.

Mr Gill refers in particular to the important right under the Citizens’ Directive for

those who have lived in the UK for five years to apply for citizenship in the following year, a right which will be lost on withdrawal. Section 7 of the Immigration Act provides that a person shall not require leave to enter or remain in

the United Kingdom “in any case in which he is entitled to do so by virtue of an
enforceable EU right”.

271. Typical is Mrs KK, a Polish national resident and working here since 2014, married to a third country national, with a Polish national child born in the UK in

2015. She feels “in a complete state of limbo” having received no assurance from

the Secretary of State as to what her status will be during and after the withdrawal negotiations, nor how her husband and child will be affected. Such people, says Mr Gill, will have made life-changing decisions and moved permanently to the UK with the ultimate intention of acquiring permanent residence. They may also find themselves exposed to criminal liability under the Immigration Act 1971 if their status is removed. Mr Gill recognises that Parliament may prior to actual withdrawal put in place a statutory protection mechanism; but that depends on the will of Parliament, which, he says, the Secretary of State cannot lawfully pre-empt. It is, he

submits, a misuse of the prerogative to “foist” such a situation on Parliament; the

rights to remain “must be addressed by Parliament before the giving of the article

50(2) notice.”

272.     There are two problems with that submission. First, it is difficult to talk of

the Executive “foisting” on Parliament a chain of events which flows directly from

the result of the referendum which it authorised in the 2015 Act. Secondly, however desirable it would be for issues of detail such as those affecting his clients to be addressed at this stage, it is wholly inconsistent with the structure of article 50. That assumes the initiation of the process by a simple notice under article 50(2), to be followed by detailed negotiations leading if possible to an agreement on the terms

of withdrawal. The details of the protections available for Mr Gill’s clients must

depend, at least in part, on the outcome of those negotiations.

273. No doubt for this reason such an extreme argument is not adopted by the other respondents. They accept that, at this stage of the article 50 process, they cannot reasonably expect anything more than bare statutory authorisation for the service of the notice. That is realistic. But it also underlines the point that successful

defence of the Divisional Court’s order will do nothing to resolve the many practical

issues which will need to be addressed over the coming period, nor to protect the rights of those directly affected. Those problems, and the need for Parliament to address them, will remain precisely the same with or without statutory authorisation for the article 50 notice. If that is what the law requires, so be it. But some may regard it as an exercise in pure legal formalism.

Conclusion

274.     Shortly after the 1972 Act came into force, Lord Denning famously spoke of

the European Treaty as “like an incoming tide. It flows into the estuaries and up the

rivers. It cannot be held back …” (Bulmer Ltd v Bollinger [1974] Ch 401, 418F).

That process is now to be reversed. Hydrologists may be able to suggest an appropriate analogy. On any view, the legal and practical challenges will be enormous. The respondents have done a great service in bringing these issues before the court at the beginning of the process. The very full debate in the courts has been supplemented by a vigorous and illuminating academic debate conducted on the web (particularly through the UK Constitutional Law Blog site). Unsurprisingly, given the unprecedented nature of the undertaking there are no easy answers. In the end, in respectful disagreement with the majority, I have reached the clear conclusion that the Divisional Court took too narrow a view of the constitutional principles at stake. The article 50 process must and will involve a partnership between Parliament and the Executive. But that does not mean that legislation is required simply to initiate it. Legislation will undoubtedly be required to implement withdrawal, but the process, including the form and timing of any legislation, can and should be determined by Parliament not by the courts. That involves no breach of the constitutional principles which have been entrenched in our law since the 17th century, and no threat to the fundamental principle of Parliamentary sovereignty.

LORD HUGHES: (dissenting)

275. Some observers, who have not been provided with the very detailed arguments which have been debated before us (or the something over 20,000 pages of documents which supported those arguments) might easily think that the principal

question in this case is: “Does the 2016 referendum result not conclude the issue,

and mean that the country is bound to leave the EU?” In fact, that is not the principal

question. No-one suggests that the referendum by itself has the legal effect that a Government notice to leave the EU is made lawful. Specifically, that is not the contention of the Government, speaking through the Secretary of State for exiting the EU. The referendum result undoubtedly has enormous political impact, but it is not suggested by the Government that it has direct legal effect.

276. The principal question in this case is not whether the UK ought or ought not to leave the EU. That is a matter for political judgment, which is where the referendum comes in. Courts do not make political judgments. The question in this case is not whether, but how, the UK may lawfully set about leaving the EU, if that is the political decision made. It is about the legal mechanics of leaving.

277. As the foregoing judgments show, this case is capable of stimulating discussion on a number of legally interesting topics. There are also supplementary questions arising out of the legal positions of Scotland, Northern Ireland and Wales. But, at some risk of over-simplifying, the main question centres on two very well understood constitutional rules, which in this case apparently point in opposite directions. They are these:

Rule 1

the executive (government) cannot change law made by Act of

Parliament, nor the common law;

and

Rule 2

the making and unmaking of treaties is a matter of foreign relations
within the competence of the government.

278. Nobody questions either of these two rules. Mrs Miller relies on the first. The government relies on the second. The government contends that Rule 2 operates to recognise its power, as the handler of foreign relations, to unmake the European Treaties. Mrs Miller contends that Rule 1 shows that the power to handle foreign relations stops short at the point where UK statute law is changed.

279. Mrs Miller’s case is that because there was an Act of Parliament (the

European Communities Act 1972) to give effect to our joining the (then) EEC and to make European rules part of UK law, there has to be another Act of Parliament to authorise service of notice to leave. This is the effect, she says, of Rule 1. Thus, she says, Rule 2 is true, but does not apply.

280.     The government’s case is that the European Communities Act 1972, which

did indeed make European rules into laws of the UK, will simply cease to operate if the UK leaves. The Act was only ever designed to have effect whilst we were members of the EU. It agrees that as a government it cannot alter the law of the UK which statute has made, but it says that if it serves notice to leave the EU, and in due course we leave, it would not be altering the statute; the statute would simply cease to apply because there would no longer be rules under treaties to which the UK was a party. Thus, it says, Rule 1 does not apply and Rule 2 does.

281. Which of these arguments is correct depends in the end on the true reading of the European Communities Act 1972. Clearly, either reading is possible. The

majority judgment gives cogent expression to the conclusion that it is Mrs Miller’s

reading which is correct. For my part, for the reasons which Lord Reed very clearly sets out, I would have preferred the view that this Act was only ever to be operative for so long as the UK was a member of (first) the EEC, and now the EU. It is not helpful, particularly because this is a minority view, to repeat the analysis which Lord Reed expounds. I agree with his judgment. In short, because of Rule 1 the Act

was necessary to convert the UK’s international obligations under the various

European treaties into law with domestic effect. Without the Act, those European rules would have had effect between States at the international level but would not have been part of domestic UK law and so would not have bound UK citizens individually. But the Act is couched in terms which give legal effect to the obligations and rules which arise under the treaties. If the UK leaves the EU, there are no longer any treaties to which this country is a party. It seems to me to follow that the Act will cease to import any of the rules which presently it does. The Act is not changed; it does, however, cease to operate because there are no longer any treaty rules for it to bite upon.

282. Thus I would, for myself, have allowed the appeal of the Secretary of State from the decision of the (English) Divisional Court. I agree that on either view of the principal Miller appeal, the devolution questions raised should all be answered

“no”, for the reasons set out in the majority judgment. I likewise agree with the

majority’s treatment of the Sewel convention.

283. It remains only to add that the arguments before us made it clear that whatever the outcome of the Miller appeal, much the same legislative programme will be

required in Parliament, upon the UK’s departure from the EU, to deal with the

multifarious legal rules presently operative via the 1972 Act. The issues before this court do not touch this exercise, which will be a matter in any event for Parliament. The court is concerned only with the necessary procedure for the service of an article 50 notice to leave.