The referendum is used in Australia as part of the formal process of amending the Commonwealth Constitution. Section 128 of the Constitution requires that a proposal to amend the Constitution must first take the form of a Bill submitted to the Commonwealth Parliament. Between two and six months after it leaves the Parliament, the proposal 'shall be submitted' to the voters in the States and Territories in the form of a referendum.
The Constitution originally provided that Bills to alter the Constitution had to be approved by referendum in a majority of States and by a majority of all electors voting. Following an amendment in 1977, the Constitution now allows electors in the Territories, as well as electors in the States, to vote in constitutional referendums. Territory votes are included in the national total only. No proposed amendment diminishing the proportionate representation of any State in either House of the Parliament, or the minimum number of representatives of a State in the House of Representatives, or altering the boundaries of a State, may become law unless the majority of the electors voting in that State approve the proposed law.
The Referendum (Machinery Provisions) Act 1984 provides the machinery for conducting referendums. Constitutional referendums have been held on nineteen separate occasions, involving forty-four separate amendment attempts.
Only eight of the forty-four proposals have been carried by referendum: