The Australian Constitution can only be amended with the approval of Australian voters. Therefore, any proposed alteration must be put to the vote at a referendum.
Section 128 of the Constitution provides that any proposed amendment to the Constitution must be passed by an absolute majority in both Houses of the Commonwealth Parliament.
In certain circumstances, a proposed amendment can be submitted to a referendum if it is passed on two separate occasions by only one House of the Parliament.
At the referendum the proposed alteration must be approved by a 'double majority'. That is:
Since Federation, only eight out of 44 proposals to amend the Constitution have been approved (see Referendum dates and results).
Voting in referendums is compulsory for enrolled voters. In referendums, voters are required to write either 'yes' or 'no' on the ballot paper in response to each question listed.
Rules governing referendums are included in the Referendum (Machinery Provisions) Act 1984.
A referendum must be held no sooner than two and no later than six months after the proposal is passed by Parliament. The main stages are:
An issue put to the vote which does not affect the Constitution is called an advisory referendum or a plebiscite.
Governments can hold advisory referendums to test whether people either support or oppose a proposed action on an issue. The government is not bound by the 'result' of an advisory referendum as it is by the result of a Constitutional referendum. Federal, state and territory governments have held advisory referendums on various issues.
Military service plebiscites were held in 1916 and 1917 but, as they were not proposals to amend the Constitution, the provisions of section 128 of the Constitution did not apply. Voters in all federal territories were permitted to vote. Both the military service plebiscites sought a mandate for conscription and were defeated.
|Name||Issue of writ||Polling day||Result|
|Military Service||18 September 1916||28 October 1916||Not Carried|
|Military Service||10 November 1917||20 December 1917||Not Carried|
ACT voters voted 'no' to self-government for the ACT in a referendum held in 1978; nevertheless the Federal Parliament legislated for ACT self-government in 1988.
ACT voters voted in favour of a proportional representation (Hare-Clark) electoral system for Legislative Assembly elections in a referendum held in 1992. The ACT government decided to introduce the Hare-Clark system.
Voters in Western Australia and Queensland have, at various times, voted in previous referendums on the issue of daylight saving; on each occasion voters rejected daylight saving and the governments decided against its introduction.