Whenever a vacancy occurs in the House of Representatives because of the death, resignation, absence without leave, expulsion, disqualification or ineligibility of a Member, a writ may be issued by the Speaker for the election of a new Member. A writ may also be issued when the Court of Disputed Returns declares an election void.

A by-election may be held on a date to be determined by the Speaker or in his or her absence from Australia by the Governor-General in Council. The polling must take place on a Saturday.

A by-election writ may also be issued by the Acting Speaker performing the duties of the Speaker during the Speaker’s absence from the Commonwealth. A writ has been issued by the Chairman of Committees as Deputy Speaker during the Speaker’s absence from the Commonwealth, and the Chairman of Committees as Deputy Speaker has informed the House of the Speaker’s intention to issue a writ.

There are no constitutional or statutory requirements that writs be issued for by-elections within any prescribed period.

The following cases have occurred:

• with a general election pending, the Speaker has declined to issue a writ in order to avoid the need for two elections within a short period of time; and
• a writ has been issued and then withdrawn by the Speaker when a dissolution of the House has intervened.

The guiding principle in fixing the date of a by-election has always been to hold the election as early as possible so that the electors are not left without representation any longer than is necessary.

Supplementary elections - background

A supplementary election must be held if a candidate for a House of Representatives election dies in the period between close of nominations and polling day, as the election is deemed to have wholly failed. A new writ is issued for another election in that division, but the election is held using the electoral roll prepared for the original election. This provision is found in Section 181 of the Commonwealth Electoral Act.

Section 181 was introduced in its current format in 1928 following the automatic election of Nationalist Party candidate, Mr G Francis, to the safe Labor seat of Kennedy after the death of the Labor candidate, Mr Charles McDonald, the day before polling day in the 1925 general election. As only two candidates nominated for the seat (from the Labor and Nationalist parties) the Nationalist member was automatically elected under the law of the day.

The first supplementary election occurred in the division of Hume in 1972, but as it was held on the same day as the 1972 general election (2 December), it was not classified as a separate election. This could not happen now because of the minimum 33-day timetable between the issue of the writ and polling day.

If a candidate for a Senate election dies in the period between close of nominations and polling day, and the number of remaining candidates is not greater than the number of candidates to be elected, those candidates are declared elected. However, if the remaining candidates are greater in number than the number of candidates to be elected, the election proceeds. A vote recorded on a Senate ballot paper for the deceased candidate is counted to the candidate for whom the voter has recorded the next preference, and the numbers indicating subsequent preferences are regarded as altered accordingly.

List of supplementary elections held

Newcastle 1998 election	Original election dates	Supplementary dates
Close of nominations:	10 September 1998	29 October 1998
Polling day:	3 October 1998	21 November 1998
Return writ by:	9 December 1998	1 December 1998

Dickson 1993 election	Original election dates	Supplementary dates
Close of nominations:	19 February 1993	26 March 1993
Polling Day:	13 March 1993	17 April 1993
Return writ by:	16 May 1993	16 June 1993

Hume 1972 election	Original election dates	Supplementary dates
Close of nominations:	10 November 1972	21 November 1972
Polling day:	2 December 1972	2 December 1972
Return writ by:	31 January 1973	31 January 1973