Double Dissolution

Fact Sheet – Double Dissolution [PDF 477kb, 2 pages]

A double dissolution occurs when both the Senate and the House of Representatives are shut down (dissolved), in order for a federal election to take place. A double dissolution election is different to regular elections, when only half the Senate seats are contested. In a double dissolution, the Governor-General dissolves both the Senate and the House of Representatives at the same time, meaning every seat in both chambers is contested. This is the only time that all senators stand for election at the same time (see Federal Elections).

A double dissolution can only happen when there is a deadlock between the two houses of Parliament; it usually occurs at the request of the Prime Minister.


The Australian Constitution gives almost identical powers to the House of Representatives and the Senate. A bill (proposed law) must be agreed to by both houses in order to become law. The drafters of the Constitution saw the possibility of a deadlock occurring between the two houses, in which there may be disagreement over a bill. Section 57 of the Constitution provides a mechanism to resolve the disagreement, by dissolving both houses of Parliament and calling an election to let the voters decide what the outcome will be. The double dissolution mechanism only relates to a bill that originates in the House of Representatives.


Section 57 of the Australian Constitution details the conditions for a double dissolution:

  1. The House of Representatives passes a bill and sends it to the Senate.
  2. The Senate rejects or fails to pass the bill, or passes it with amendments to which the House will not agree.
  3. Three months pass from the time the Senate disagrees with the bill.
  4. The House of Representatives passes the same bill and sends it to the Senate again.
  5. The Senate again rejects or fails to pass the bill, or passes the same bill with amendments to which the House will not agree.

Once these conditions (called triggers) have been met, the Prime Minister may recommend to the Governor-General that a double dissolution of the Parliament take place. A federal election then follows for all members of the House of Representatives and all senators.

More than one bill may act as a trigger for a double dissolution.

A double dissolution cannot take place within six months of the end of a three-year term of the House of Representatives.

Joint sitting of Parliament

After a double dissolution election, the bill(s) which triggered the double dissolution may be presented to both houses of Parliament again. If a deadlock occurs once more, the Governor-General may order a joint sitting of both houses of Parliament. At a joint sitting, all members of parliament from both houses meet together to vote on the bill(s). A joint sitting has only occurred once in the Australian Parliament, in 1974.

In this instance, the government led by Prime Minister Gough Whitlam had a majority of nine votes in the House of Representatives but did not have a majority in the Senate. By April 1974, the Senate had twice refused to pass six bills and these became double dissolution triggers. The Prime Minister requested the Governor-General to use section 57 to dissolve both houses of Parliament and call an election for 18 May.

The government won the election but with a reduced majority in the House of Representatives; it still did not have a majority in the Senate. The disputed bills were again introduced into and passed by the House of Representatives. The Senate again rejected the bills. As a result, the Governor-General convened a joint sitting of both houses of Parliament on Tuesday 6 August and Wednesday 7 August 1974 to vote together on the bills. Three of these bills related to electoral matters, two related to health insurance and one related to setting up the Petroleum and Minerals Authority. The Whitlam government held a majority of all the combined votes, with government members voting together to ensure that the six bills were passed by an absolute majority of all members of parliament.

Mr Whitlam speaks on the steps of Old Parliament House, Canberra, after his dismissal

Australian Information Service, National Library of Australia, an 24355082


There have been seven double dissolutions of the Australian Parliament: in 1914, 1951, 1974, 1975, 1983, 1987 and 2016. In 1914, 1975 and 1983, the government lost the election that resulted from the double dissolution. The most famous of these double dissolutions occurred in 1975. The Senate refused to pass the supply (Budget bills) of the government, led by Prime Minister Gough Whitlam. This caused a deadlock which could be used as a double dissolution trigger. The Prime Minister did not want a double dissolution election; however, Governor-General Sir John Kerr dismissed the government and an election was called by caretaker Prime Minister Malcolm Fraser.

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