Chapter I The Parliament
Part II The Senate
Section 15
15 Casual vacancies [see Note 8]
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:
(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