Double dissolution

Similar to the United States Congress, but unlike the British Parliament, Australia's two parliamentary houses generally have almost equal legislative power (the Senate may reject outright but cannot amend appropriation (money) bills, which must originate in the House of Representatives).

Governments, which are formed in the House of Representatives, can be frustrated by a Senate determined to reject their legislation.

The double dissolution provision comes into play if the Senate and House twice fail to agree on a piece of legislation (in section 57 called a "proposed law", and commonly referred to as a "trigger").

When one or more such triggers exist, the Governor-General may dissolve both the House and Senate – pursuant to section 57 of the Constitution – and issue writs for an election in which every seat in the Parliament is contested.

The conditions stipulated by section 57 of the Constitution are: There is no similar provision for resolving deadlocks with respect to bills that have originated in the Senate and are blocked in the House of Representatives.

However, as the 1975 constitutional crisis demonstrated, the Governor-General is not compelled to follow the Prime Minister's advice.

In these cases, he or she must be personally satisfied that the conditions specified in the Constitution apply, and is entitled to seek additional information or advice before coming to a decision.

As a High Court Chief Justice Barwick observed in a unanimous decision in Cormack v Cope (Joint Sittings Case) (1974)[1] (with emphasis added): There have been seven double dissolutions: in 1914, 1951, 1974, 1975, 1983, 1987 and 2016.

Antony Green's working guide is that "if a party has more than 0.5 of a quota, it will be in the race for one of the final seats".

This has traditionally been done by allocating long terms to the senators elected earliest in the count.

[20] Under section 41 of the South Australian constitution, if a bill is passed by the House of Assembly during a session of Parliament and in the following Parliament after a general election for the lower house is rejected by the Legislative Council on both occasions, it is permitted for the Governor of South Australia to either issue a writ for the election of 2 additional members of the Legislative Council or to dissolve both houses at the same time to elect an entirely new Parliament.