Commonwealth Electoral Act 1918

If the place of a Senator for the Australian Capital Territory becomes vacant before the expiration of his or her term of service, the Legislative Assembly for the Australian Capital Territory shall choose a person to hold the place until the expiration of the term, but 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.

If the place of a senator for the Northern Territory becomes vacant before the expiration of his or her term of service, the Legislative Assembly of the Territory shall choose a person to hold the place until the expiration of the term, but 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.

If the place of a senator for a Territory other than the Northern Territory or the Australian Capital Territory becomes vacant before the expiration of his or her term of service, 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.

Where:

in accordance with subsection (3), 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);

Whenever the place of a senator for a Territory becomes vacant before the expiration of his or her term of service:

in the case of a senator for the Australian Capital Territory—the President of the Senate shall notify the Chief Minister for the Australian Capital Territory of the vacancy;

in the case of a senator for the Northern Territory—the President of the Senate shall notify the Administrator of the Northern Territory of the vacancy; and

in the case of a senator for a Territory other than the Northern Territory or the Australian Capital Territory—the President of the Senate shall notify the Governor‑General 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 Australian Capital Territory or the Administrator of the Northern Territory, as the case may be, to the Governor‑General.

The name of any senator chosen by the members of the Senate and the House of Representatives under subsection (2A) shall be certified by the President of the Senate to the Governor‑General.

Except in so far as the contrary intention appears in this section, an expression that is used in this section and in section 15 of the Constitution has, in this section, the same meaning as in section 15 of the Constitution.