How does the government fill a Senate seat if someone resigns or dies?

In Plain English

If a Senator leaves their position before their term is finished (due to resignation, death, or other reasons), the process for replacing them depends on whether the senator represented a State or a Territory.

  • For a State Senator: The Parliament of that State chooses a replacement. If the State's Parliament isn't meeting at the time, the State's Governor can appoint someone temporarily until the Parliament can make a decision. The replacement usually has to be from the same political party as the person who left, unless there's no one available from that party. This is outlined in the Commonwealth of Australia Constitution Act and the Constitution Alteration (Senate Casual Vacancies) 1977.
  • For a Territory Senator: The process is outlined in the Commonwealth Electoral Act 1918.
    • For the Australian Capital Territory (ACT), the ACT Legislative Assembly chooses a replacement. If the Assembly isn't meeting, the Chief Minister can make a temporary appointment.
    • For the Northern Territory, the Legislative Assembly of the Northern Territory chooses the replacement, or the Administrator of the Territory can make a temporary appointment if the Assembly isn't in session.
    • For any other Territory, the members of the Senate and the House of Representatives meet together to choose a replacement. If Parliament isn't meeting, the Governor-General can make a temporary appointment.

Detailed Explanation

The process for filling a Senate vacancy is outlined in several pieces of legislation:

  • State Senator Vacancies: Section 15 of the Commonwealth of Australia Constitution Act, as amended by the Constitution Alteration (Senate Casual Vacancies) 1977, details the process for filling casual vacancies for Senators representing a State.
    • The relevant State's Parliament (or the single House, if it only has one) chooses a person to fill the vacancy until the end of the original Senator's term.
    • If the State Parliament is not in session when the vacancy occurs, the State Governor, with the advice of the Executive Council, can appoint someone to hold the place temporarily. This appointment lasts until 14 days after the beginning of the next session of the State Parliament, or until the end of the term, whichever comes first.
    • The replacement must be from the same political party as the original Senator, provided a member of that party is available. If the replacement ceases to be a member of that party before taking their seat (other than by reason of the party ceasing to exist), they are deemed not to have been chosen, and the vacancy is notified again.
    • The Governor of the State certifies the name of the chosen or appointed Senator to the Governor-General.
  • Territory Senator Vacancies: Section 44 of the Commonwealth Electoral Act 1918 outlines the process for filling vacancies for Senators representing a Territory.
    • For the Australian Capital Territory, the Legislative Assembly for the Australian Capital Territory chooses a person to hold the place until the expiration of the term. If the Legislative Assembly is not in session when the vacancy is notified, the Chief Minister for the Australian Capital Territory may appoint a person to hold the place until the expiration of 14 days from the beginning of the next session of the Legislative Assembly or the expiration of the term, whichever first happens.
    • For the Northern Territory, the Legislative Assembly of the Territory chooses a person to hold the place until the expiration of the term. If the Legislative Assembly is not in session when the vacancy is notified, the Administrator of the Territory, with the advice of the Executive Council thereof, may appoint a person to hold the place until the expiration of 14 days from the beginning of the next session of the Legislative Assembly or the expiration of the term, whichever first happens.
    • For a Territory other than the Northern Territory or the Australian Capital Territory, the members of the Senate and the House of Representatives, sitting and voting together at a joint sitting convened by the Governor-General, shall choose a person to hold the place until the expiration of the term, but if the Parliament is not in session when the vacancy is notified, the Governor-General may appoint a person to hold the place until the expiration of 14 days from the beginning of the next session of the Parliament 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 Territory and, when chosen, the senator was publicly recognized by a particular political party as being an endorsed candidate of that party and publicly represented himself or herself 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.
    • If a person who is a member of a particular political party is chosen or appointed to hold the place of a senator whose place had become vacant, and before commencing to hold the place, the person ceases to be a member of that party (otherwise than by reason of the party having ceased to exist), the person shall be deemed not to have been so chosen or appointed and the vacancy shall be again notified.
    • Whenever the place of a senator for a Territory becomes vacant before the expiration of his or her term of service, the President of the Senate shall notify the relevant authority of the vacancy.
    • The name of any senator chosen or appointed under subsection (1) or (2) shall be certified by the Chief Minister for the or the Administrator of the , as the case may be, to the Governor-General.