Eight by-elections that changed the game

Section 44 of the Constitution prevents dual citizens being elected to Parliament.

Four of those five were Senators but one, Barnaby Joyce, was a Member of Parliament which meant a by-election was held in the seat of New England on 2 December. Since October another MP, John Alexander, declared himself ineligible, with the by-election for his seat of Bennelong held on 16 December.

By-elections are fairly common in Australia, and only one Parliament (the 43rd) since 1951 has seen none at all. A by-election follows all the rules of a general election, except that it is held in just one seat. For this reason by-elections tend to receive large amounts of media coverage. Voters in by-elections tend to use them to send a message to one or the other side of politics, which can result in large, devastating swings.

Here are eight historic examples of by-elections that changed the game.

Very close elections are usually voided, because the Court of Disputed Returns (the High Court) finds anomalies or mistakes with the count. One of the most notable examples was in Ballaarat (spelled with an extra 'a' until 1977) in 1920. At the general election the previous year, Nationalist Edwin Kerby had won against Labor incumbent Charles McGrath by a single vote. This remains the closest victory in history. However, the court found there were several irregularities with the count and ordered a do-over. McGrath won, this time substantially.

This kind of by-election had also happened in Melbourne and Riverina in 1904, and Echuca in 1907.

Bass, 1975

Voters in northern Tasmania decided to put the boot into the Whitlam government in June 1975. Whitlam's former loyal deputy, Lance Barnard, resigned from the House to become Ambassador to the Scandinavian countries. Barnard had held the seat since 1954 and had almost always won it handily. At the by-election, however, voters decided to punish the government which was becoming highly unpopular. The Liberal candidate, Kevin Newman, won Bass with a 17.5% swing, turning it from a safe Labor to a safe Liberal seat overnight. The Bass result is usually described as the beginning of the end for the Whitlam government.

Wills, 1992

As long as we're talking about ineligibility, the High Court's recent decision builds on one it made in 1993 after the election of Phil Cleary. Cleary, a former VFL footballer and teacher, stood for the seat of Wills in inner Melbourne when Bob Hawke resigned from Parliament in June 1992. Twenty-two candidates contested, the largest number ever for one seat, and Cleary won as an Independent. Immediately, his election was challenged on the basis that as a teacher he was an employee of the Department of Education and thus had an 'office of profit under the crown', which made him ineligible for election under Section 44 of the Constitution. The High Court agreed in November. Cleary waited patiently until the 1993 federal election, when he stood for Wills again and won.

A very similar situation occurred in Lindsay in Western Sydney in 1996. Liberal candidate Jackie Kelly had won the seat at the March general election but was ruled ineligible due to having New Zealand citizenship and was employed by the Royal Australian Air Force. The election was re-run and Kelly won.

Cunningham, 2002

The Australian Greens won their first-ever House of Representatives seat in 2002 when a by-election was held in Cunningham, New South Wales. Labor's Stephen Martin had resigned and the Liberals opted not to run a candidate in the safe Labor seat. A high protest vote against Labor, which was suffering poor polling, saw Green Michael Organ elected with just 23% of the primary vote. Organ only held the seat until Labor regained it in 2004, but it remains a rare example of an opposition seat falling to a third-party challenger.

Canning, 2015

The death of Don Randall in 2015 triggered a by-election in his seat of Canning in suburban Perth. Liberal candidate Andrew Hastie was facing a fight in the normally safe seat, as polling was not good for the Abbott government, with one poll suggesting a 10% swing or more. Such a drastic swing, and only two years into a government's first term, could have spelled disaster. Exactly how much impact the impending by-election had on the Liberal Party's decision to replace Abbott with Malcolm Turnbull is disputed. However, following Hastie's victory, many media reports focused on the transfer to Turnbull as the only thing that saved the seat for the Coalition.