Double dissolution

In accordance with section 57 of the Constitution the Governor-General, at the request of the Prime Minister, dissolved the Senate and the House of Representatives at 9am on 9 May 2016.

This dissolution brings to an end all proceedings of the Senate, the House and all committees.

Background  |  What now?  |  Section 57  |  Historic examples


On 8 May 2016, the Prime Minister wrote to the Governor-General:

I am able to advise that all conditions for a double dissolution have been met with respect to two parcels of legislation: the Building and Construction Industry (Improving Productivity) Bill 2013 and the Building and Construction Industry (Consequential and Transitional Provisions) Bill 2013 ("ABCC Bills") and the Fair Work (Registered Organisations) Amendment Bill 2014 ("Registered Organisations Bill").

The Senate has, on two occasions, rejected each of the ABCC Bills and the Registered Organisations Bill. The requirement in section 57 that there be an interval of at least three months between the first rejection by the Senate and the second passage by the House of Representatives has been met in respect of each of those Bills.

A double dissolution election will be held on 2 July 2016.

What now? The effect of a double dissolution

The House of Representatives

Under section 28 of the Constitution, the House of Representatives may last for no more than three years after the date of its first meeting after an election. The House then expires automatically if not dissolved sooner by the Governor-General, on the advice of the Prime Minister.

Expiry or dissolution triggers the issuing of writs for a general election to elect all 150 members of the House. After dissolution, the terms of service of all members cease, bills and all other business before the House of Representatives lapse, and, if required, would need to be reinitiated in the next Parliament.

The Senate

In contrast, under a normal electoral cycle the Senate is a continuing house. The term of a state senator is six years commencing on 1 July following a general election. Six of the twelve places from each state are contested at each alternate election. The four territory senators serve the same terms as members of the House of Representatives.

A double dissolution brings an end to the term of service of all 76 senators and an election for the full membership is held.

Terms of service of senators

The terms of senators elected in the double dissolution election will commence on 1 July 2016. The state senators will be divided into two classes: short-term senators whose terms expire on 30 June 2019, and long-term senators whose terms expire on 30 June 2022. It is a matter for the Senate to decide how this division takes place. However, on the seven previous occasions that it has been necessary to divide the Senate for the purposes of rotation, the practice has been to allocate senators according to the order of their election. For example, following the simultaneous dissolution in 1974, the Senate resolved that “the name of the Senator first elected shall be placed first on the Senators’ Roll for each State and the name of the Senator next elected shall be placed next, and so on in rotation”.


In the course of a normal general election, House and Joint committees cease to exist and all current inquiries lapse, but Senate committees may continue to function. Following a double dissolution, Senate committees also cease to exist and all current inquiries lapse.

At the commencement of a new parliament, a committee may seek to re-adopt an inquiry from the previous parliament. See, for example, Journals of the Senate, 14 November 2013.

Caretaker Government

After both Houses are dissolved, the government becomes a caretaker government and, by convention, does not make major decisions, except in consultation with the opposition.

For more information on government guidelines and procedures, including on the Caretaker conventions, visit the Department of Prime Minister and Cabinet website.

Section 57 of the Constitution

Section 57 sets out the steps for resolving a disagreement involving a proposed law originating in the House of Representatives. The procedure does not apply to a bill originating in the Senate.

Double dissolution

  1. The House of Representatives passes a bill and sends it to the Senate.
  2. The Senate rejects the bill, or fails to pass it, or passes it with amendments to which the House will not agree.
  3. After three months the House of Representatives passes the bill a second time and sends it to the Senate again.
  4. The Senate again rejects the bill, or fails to pass it, or passes it with amendments to which the House will not agree.
  5. The Prime Minister may now advise the Governor-General to dissolve both Houses, this is a matter for determination by the Prime Minister.
  6. If the Prime Minister takes that step, both Houses are dissolved simultaneously and elections are held for both Houses

After the elections for both Houses

  1. In the new Parliament, the House of Representatives passes the bill again and sends it to the Senate.
    There is no constitutional necessity to reintroduce a bill that was the cause of a double dissolution.
  2. The Senate again rejects the bill, or fails to pass it, or passes it with amendments to which the House will not agree.

Joint sitting

  1. The Prime Minister may now advise the Governor-General to convene a joint sitting of the members of both Houses.
  2. The members of both Houses at the joint sitting vote on the bill. To be passed it must be agreed to by an absolute majority - that is, more than half of the total number of members of both Houses.

Historic examples

Double dissolutions have occurred six times during the history of the federal Parliament: 1914, 1951, 1974, 1975, 1983 and 1987. The only occasion on which a joint sitting was subsequently held, was 6 August 1974.

For more information on previous double dissolutions, see: