Constitution Alteration (Senate Casual Vacancies) 1977

Administered by Attorney-General's Department

Legislation au C2004A01720 In force Act

Legislation content

CONSTITUTION ALTERATION (SENATE CASUAL VACANCIES) 1977

No. 82 of 1977

An Act to alter the Constitution so as to ensure so far as practicable that a Casual Vacancy in the Senate is filled by a Person of the same Political Party as the Senator chosen by the People and for the balance of his Term.

BE IT ENACTED by the Queen, and the Senate and House of Representatives of the Commonwealth of Australia, with the approval of the electors, as required by the Constitution, as follows:

Short title.

1. This Act may be cited as the Constitution Alteration (Senate Casual Vacancies) 1977.

2. The Constitution is altered by omitting section 15 and substituting the following section:

Casual vacancies.

15. If the place of a senator becomes vacant before the expiration of his term of service, the Houses of Parliament of the State for which he was chosen, sitting and voting together, or, if there is only one House of that Parliament, that House, shall choose a person to hold the place until the expiration of the term. But if the Parliament of the State is not in session when the vacancy is notified, the Governor of the State, with the advice of the Executive Council thereof, may appoint a person to hold the place until the expiration of fourteen days from the beginning of the next session of the Parliament of the State or the expiration of the term, whichever first happens.

Where a vacancy has at any time occurred in the place of a senator chosen by the people of a State and, at the time when he was so chosen, he was publicly recognized by a particular political party as being an endorsed candidate of that party and publicly represented himself to be such a candidate, a person chosen or appointed under this section in consequence of that vacancy, or in consequence of that vacancy and a subsequent vacancy or vacancies, shall, unless there is no member of that party available to be chosen or appointed, be a member of that party.

Where

(a) in accordance with the last preceding paragraph, a member of a particular political party is chosen or appointed to hold the place of a senator whose place had become vacant; and

(b) before taking his seat he ceases to be a member of that party (otherwise than by reason of the party having ceased to exist),

he shall be deemed not to have been so chosen or appointed and the vacancy shall be again notified in accordance with section twenty-one of this Constitution.

The name of any senator chosen or appointed under this section shall be certified by the Governor of the State to the Governor-General.

If the place of a senator chosen by the people of a State at the election of senators last held before the commencement of the Constitution Alteration (Senate Casual Vacancies) 1977 became vacant before that commencement and, at that commencement, no person chosen by the House or Houses of Parliament of the State, or appointed by the Governor of the State, in consequence of that vacancy, or in consequence of that vacancy and a subsequent vacancy or vacancies, held office, this section applies as if the place of the senator chosen by the people of the State had become vacant after that commencement.

A senator holding office at the commencement of the Constitution Alteration (Senate Casual Vacancies) 1977, being a senator appointed by the Governor of a State in consequence of a vacancy that had at any time occurred in the place of a senator chosen by the people of the State, shall be deemed to have been appointed to hold the place until the expiration of fourteen days after the beginning of the next session of the Parliament of the State that commenced or commences after he was appointed and further action under this section shall be taken as if the vacancy in the place of the senator chosen by the people of the State had occurred after that commencement.

Subject to the next succeeding paragraph, a senator holding office at the commencement of the Constitution Alteration (Senate Casual Vacancies) 1977 who was chosen by the House or Houses of Parliament of a State in consequence of a vacancy that had at any time occurred in the place of a senator chosen by the people of the State shall be deemed to have been chosen to hold office until the expiration of the term of service of the senator elected by the people of the State.

If, at or before the commencement of the Constitution Alteration (Senate Casual Vacancies) 1977, a law to alter the Constitution entitled Constitution Alteration (Simultaneous Elections) 1977 came into operation, a senator holding office at the commencement of that law who was chosen by the House or Houses of Parliament of a State in consequence of a vacancy that had at any time occurred in the place of a senator chosen by the people of a State shall be deemed to have been chosen to hold office

(a) if the senator elected by the people of the State had a term of service expiring on the thirtieth day of June, One thousand nine hundred and seventy-eight—until the expiration or dissolution of the first House of Representatives to expire or be dissolved after that law came into operation; or

(b) if the senator elected by the people of the State had a term of service expiring on the thirtieth day of June, One thousand nine hundred and eighty-one—until the expiration or dissolution of the second House of Representatives to expire or be dissolved after that law came into operation or, if there is an earlier dissolution of the Senate, until that dissolution..

 

Overview

The Constitution Alteration (Senate Casual Vacancies) Act 1977 was enacted to address the issue of filling casual vacancies in the Senate with a senator from the same political party as the original elected senator. This Act was introduced to ensure that, as far as practicable, the balance of political representation within the Senate remains consistent with the electorate's original choice. The legislation was enacted by the Queen, with the approval of both the Senate and House of Representatives of the Commonwealth of Australia, in accordance with the constitutional requirement for altering the Constitution. The primary policy objective of this Act is to maintain political integrity within the Senate by ensuring that any casual vacancy is filled by a member of the same political party as the original senator, thus reflecting the electorate's original preference.

Scope and Application

The Constitution Alteration (Senate Casual Vacancies) 1977 amends the Australian Constitution to address the filling of casual vacancies in the Senate, ensuring that the replacement senator is from the same political party as the original senator, to the extent practicable. This Act applies to the process of filling casual vacancies in the Senate, a body that is part of the Commonwealth Parliament. Specifically, it concerns the selection or appointment of a senator to fill a vacancy that occurs before the expiration of a senator's term. The process outlined in the Act involves either the Houses of Parliament of the relevant state choosing a new senator, or the Governor of the state appointing a senator if the Parliament is not in session, subject to certain conditions regarding the political party affiliation of the chosen or appointed senator. The Act applies to all states within the Commonwealth of Australia, and its provisions are designed to maintain the political balance within the Senate. There are no stated exclusions or exemptions within the Act, though it does provide specific rules for scenarios where the vacancy occurs before or after certain significant dates related to the operation of other constitutional amendments.

Key Provisions

The Constitution Alteration (Senate Casual Vacancies) 1977 (section 2) amends section 15 of the Constitution, which deals with the filling of casual vacancies in the Senate. Under the new provisions, if a senator’s place becomes vacant before the end of their term, the Parliament of the state concerned must select a replacement. If the Parliament is not in session, the Governor of the state, with advice from the Executive Council, can temporarily fill the vacancy for up to fourteen days or until the next parliamentary session, whichever is sooner (section 15(2)). Importantly, if the original senator was a member of a particular political party, the replacement must also be a member of that party, unless no such member is available (section 15(3)). If the replacement leaves the party before taking their seat, they are deemed never to have been chosen or appointed, and a new vacancy is created (section 15(4)). The Act imposes obligations on several entities. The Parliament of the state where the vacancy occurs must convene to select a replacement senator if they are in session, while the Governor, advised by the Executive Council, must step in if the Parliament is not in session (section 15(2)). The political party that originally endorsed the vacating senator must ensure that a member of their party is available to fill the role, unless no such member exists (section 15(3)). The Governor is tasked with certifying the name of the chosen or appointed senator to the Governor-General (section 15(5)). There are no explicit offences, penalties, or consequences for breach outlined in the Act. However, failing to adhere to the procedures for filling casual vacancies as stipulated could lead to legal challenges and potential judicial review, as the Act aims to maintain the integrity and continuity of political representation in the Senate.

Legal classification tags

Area of Law
Constitutional Law
Instrument
Act
Concepts
Definitions & Interpretation
Commencement Provisions
Repeal & Amendment
Prohibited Conduct

Interactions

Authorises

All Versions

Sourced from the Federal Register of Legislation at 26 August 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au.