From the beginning of Federation until 1918,
first-past-the-post voting was used in order to elect members of the House of Representatives but since the
1918 Swan by-election which
Labor unexpectedly won with the largest primary vote due to vote splitting amongst the conservative parties, the
Nationalist Party government, a predecessor of the modern-day
Liberal Party of Australia, changed the lower house voting system to
full preferential voting, as of the subsequent
1919 election. This system has remained in place ever since, allowing the
Coalition parties to safely contest the same seats. Full-preference preferential voting re-elected the
Hawke government at the
1990 election, the first time in federal history that Labor had obtained a net benefit from preferential voting. From 1949 onwards, the vast majority of electorates, nearly 90%, are won by the candidate leading on first preferences, giving the same result as if the same votes had been counted using first-past-the-post voting. The highest proportion of seats (up to 2010) won by the candidate not leading on first preferences was the
1972 federal election, with 14 of 125 seats not won by the plurality candidate.
Allocation process for the House of Representatives The main elements of the operation of preferential voting for single-member House of Representatives divisions are as follows: • Voters are required to place the number "1" against their first choice of candidate, known as the "first preference" or "primary vote". • Voters are then required to place the numbers "2", "3", etc., against all of the other candidates listed on the ballot paper, in order of preference.
Every candidate must be numbered, otherwise the vote becomes "informal" (spoiled) and does not count.) • Prior to counting, each ballot paper is examined to ensure that it is validly filled in (and not invalidated on other grounds). • The number "1" or first preference votes are counted first. If no candidate secures an absolute majority (more than half) of first preference votes, then the candidate with the fewest votes is excluded from the count. • The votes for the eliminated candidate (i.e. from the ballots that placed the eliminated candidate first) are re-allocated to the remaining candidates according to the number "2" or "second preference" votes. • If no candidate has yet secured an absolute majority of the vote, then the next candidate with the fewest primary votes is eliminated. This preference allocation is repeated until there is a candidate with an absolute majority. Where a second (or subsequent) preference is expressed for a candidate who has already been eliminated, the voter's third or subsequent preferences are used. Following the full allocation of preferences, it is possible to derive a
two-party-preferred figure, where the votes have been allocated between the two main candidates in the election. In Australia, this is usually between the candidates from the
Coalition parties and the
Australian Labor Party. ==Relationship with the government==