What is a referendum?

A referendum in Australia is a direct vote of the people on a specific question, typically a proposed change to the federal Constitution. Federal referendums are held under section 128 of the Constitution and are the only way the Constitution can be amended. The Australian Electoral Commission runs federal referendums on the same compulsory-voting basis as ordinary federal elections.

The federal referendum process begins in Parliament. A constitutional alteration bill must be passed by an absolute majority of both Houses of the federal Parliament (or alternatively by one House twice with a deadlock-breaking mechanism). The bill is then presented to the Governor-General, who issues a writ for the referendum. The referendum must be held not less than two months and not more than six months after the bill has been passed. Voters answer Yes or No to specific question text drawn from the bill.

Each federal referendum requires the double majority to pass: a national majority of voters plus a majority of voters in at least four of the six states. Voters in the two mainland territories count toward the national total but not the state-by-state count. Of the 45 referendum questions held since federation, only 8 have been carried. The most famous successful referendum was the 1967 vote that recognised Aboriginal people in the Constitution, carried with 90.77 per cent Yes (the highest Yes vote of any Australian referendum). The most recent referendum, on 14 October 2023, proposed an Aboriginal and Torres Strait Islander Voice to Parliament and was defeated nationally with 60.1 per cent No, and carried in no state.

Referendums also operate at state level under state-based constitutional amendment provisions, although they are less common. State referendums have addressed matters including the date of state elections, the size of state parliaments, and (in NSW in 1995) the four-year fixed term for state elections. Plebiscites are non-binding national votes that advise government on a particular question without changing the Constitution. The 2017 Australian Marriage Law Postal Survey on same-sex marriage (carried with 61.6 per cent Yes) is the most recent famous example. Plebiscites do not produce binding legal change, although they politically commit governments to act on the result.