[2] Prior to the amendment: The amendment changed this procedure by providing that: Its intended purpose was to prevent major changes in the balance of power in the senate in the middle of a parliamentary term, but as it did not provide any time limit within which the appointment had to be made, the state legislature remained free to decline to fill the vacancy.

As Section 11 of the Constitution permits the Senate to carry on despite the failure to fill any vacancy, the amendment did not completely solve the problem.

These concerned the: The casual vacancies amendment came about as part of the political fallout from both the Gair Affair and the Australian constitutional crisis of 1975.

In the aftermath of this crisis, four amendments were recommended by sessions of the Australian Constitutional Convention, including one that would change the procedure for appointing replacement senators.

Section 15 (before) 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 shall, sitting and voting together, choose a person to hold the place until the expiration of the term, or until the election of a successor as hereinafter provided, whichever first happens.

Where- 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.