What is a by-election in Australia?
Answer
An election held in one electorate between federal elections
Explanation
A by-election in Australia is an election held in a single electorate to fill a vacancy that has arisen between general elections. By-elections happen when a sitting member of the House of Representatives dies, resigns, is disqualified, or is removed from office during a parliamentary term. The Senate follows different rules: Senate vacancies are filled by the relevant state Parliament, not by by-election.
By-election triggers are specified by the Commonwealth Electoral Act 1918. A by-election must be called if a member of the House of Representatives leaves their seat for any reason during the term of the Parliament. The Speaker, on advice from the AEC, advises the Governor-General to issue a writ for a by-election. The writ specifies the close of rolls, the date of nomination, the date of polling, and the date for returning the writ. The same AEC processes for nomination, voting, and counting apply as in general elections.
Recent federal by-elections include the Aston by-election in April 2023 (won by Labor's Mary Doyle from the Coalition, the first time a government had won a seat from the opposition at a by-election in more than 100 years), the Fadden by-election in July 2023 (won by the Coalition's Cameron Caldwell), and the Dunkley by-election in March 2024 (won by Labor's Jodie Belyea). Each by-election attracts intense media attention as a referendum on the government and as a test of party fortunes between general elections.
By-elections have several distinctive features. Turnout is compulsory but typically lower than general elections (around 85 to 90 per cent compared to 92 per cent at general elections). Smaller numbers of candidates often run. Major parties sometimes choose not to contest if they consider the seat lost, though this is becoming less common. The 2017 to 2018 dual citizenship crisis produced ten Senate replacements and a series of House by-elections including Bennelong (December 2017, won by John Alexander returning after his dual citizenship was resolved). Senate vacancies are now resolved through casual vacancy replacements: state parliaments appoint a replacement from the same party as the departing senator under section 15 of the Constitution as amended in 1977.
Why this matters for your test
By-elections fill vacancies during a parliamentary term and often signal shifts in political support, and recognising the Senate's different replacement process completes the picture.
Source: Australian Citizenship: Our Common Bond (2024)
