Research Report 4 - Australian Federal Redistributions 1901-2003: Origins of the Australian Redistribution Process

Updated: 30 May 2013

Origins of the Australian Redistribution Process

The first distribution for federal parliament occurred in 1900 when 3 of the original states, New South Wales, Victoria, Queensland, as well as Western Australia, had electoral boundaries determined by their respective State Parliaments. However, the first distribution under actual federal legislation occurred in 1903 when Tasmania and South Australia had their single electorate abolished and multiple electorates created. For the first federal election in 1901, electors in Tasmania and South Australia voted as 1 division in each state.

Since Federation there have been 111 distribution/redistribution reports written which resulted in 2 initial distributions (South Australia and Tasmania)[2], 76 redistributions, 14 lapsed reports and 19 rejected reports. In addition there has been 1 revision to original boundaries (the Northern Territory in 2004). The redistribution summaries in this report only reflect the successful distributions and redistributions[3]. Between 1901 and 1984 the average time between redistributions was 8.8 years[4]. Since 1984 the time between redistributions has been reduced to a maximum of 7 years.

Since Federation there have been four significant procedural changes and one machinery of government change that has affected the Australian procedure for calculating and conducting a redistribution:

  • 1948 The number of Senators was increased for the states from 5 to 10 for the original states thereby increasing the number of Members for all the states and territories, from 75 to 123. This initiated a general redistribution in all states.
  • 1974 The permissible variation of the quota was reduced from 20 percent to 10 percent and the Northern Territory and the ACT each were entitled to 2 Senators to be elected at each general election.
  • 1977 The High Court ruled that the 4 Senate places created in 1974 for the Australian Capital Territory and the Northern Territory could not be used for the purposes of calculating the number of Members for the House under the nexus provision of the Constitution. As a result the number of Members was reduced at the next election from 127 to 124[5].
  • 1983 The number of senators, for the original states, was increased from 10 to 12, bringing the total for all the states to 72, with 4 from the territories making a total of 76, although the territory Senators are not included in the calculation of Member entitlement. As a result the number of members increased from 125 to 148.
  • 1984 The Australian Electoral Commission (AEC) was created as an independent Statutory Authority out of the then Australian Electoral Office. The most significant change was that the AEC, now being an independent government agency, is not subject to ministerial direction, as its predecessor was, and the AEC is charged solely with the responsibility of conducting a redistribution. Redistributions were no longer subject to approval or disapproval of the Parliament.

Parliamentary Procedure

Prior to the 1983 amendments to the legislation, redistributions were subject to the approval, by a resolution, of each house of Parliament. If either house disapproved or negated the proposal the Minister could direct a fresh redistribution report; such was the case in 1912, 1936, and 1968. There were also instances where Parliament took no final action regarding redistribution reports in 1905 and 1931 and one instance where a proposal was being debated but lapsed because of the dissolution of Parliament in 1962. There have also been several occasions were proposed boundaries were adopted but Parliament changed the proposed names of the divisions[6].

The Nexus Provision

Section 24 of the Constitution requires that the number of Members of the House of Representatives must be twice the number of Senators, or as near as practicable. This provision is usually referred to as the nexus provision. This prevents the House of Representatives becoming at any time disproportionately large in relation to the Senate. The Parliament may legislate to change the number of the members of both Houses, and it has done so on two occasions since federation, in 1948 and again in l983. It does this by changing the number of Senators representing each state, which automatically allows a proportionate change in the number of Members of the House of Representatives.

There are currently 150 Members of the House of Representatives (as at December 2003), just over twice the number of the Senators (72) who represent the six states[7]. The remaining 4 members represent the territories with 2 members elected from each territory.

The size of the Senate was 36 from 1901 until 1949; 60 from 1950 to 1975; 64 from 1976 to 1984; and 76 since 1985[8]. Since 1975, 4 senators have been elected at every House of Representatives election for the ACT and the Northern Territory.

Timing of redistributions

Redistributions of the electoral boundaries take place periodically to ensure that all Australians receive equal representation in Parliament. Since 1983 the Act provides for three triggers for a redistribution of federal electoral boundaries. Under Section 59 of the Act a redistribution commences whenever the Electoral Commission publishes a direction in the Commonwealth Gazette. Such a direction is made when:

  • the number of Parliamentary representatives to which a State or Territory is entitled to changes (population change)
  • the number of electors in more than one-third of the divisions in a State or Territory deviates from the average divisional enrolment by over ten per cent for more than two consecutive months (malapportionment)
  • seven years has elapsed since the last redistribution.

However, a direction under the last two circumstances will not be made if a State or Territory is already undergoing redistribution, or within the last 12 months of the life of a House of Representatives (that is, more than two years after its first meeting).

Calculation of Apportionment

The procedure for determining the apportionment (or entitlement) in the House of Representatives is contained in section 48 of the Act and section 24 of the Australian Constitution.

The Act requires that during the thirteenth month after the first meeting of the newly elected House of Representatives, the Electoral Commissioner ascertains the population of the Commonwealth (excluding the Territories) according to the latest official statistics available from the Australian Statistician. The Commissioner then makes a determination of the number of Parliamentary representatives to which each State is entitled. A similar exercise is used to calculate the entitlements of the Territories.

The calculation is as follows:

Step One:

The population of the six States is divided by twice the number of Senators for the States.

Total population of the six States ÷ (2 x number of Senators for the States = 144) = Apportionment Quota

For example the calculation of the Quota in February ( the 13th month following the 1st day of sitting of the 40th Parliament) was as follows:

19 205 190 ÷ (72 x 2 = 144) = 133 369.375

Step Two:

The population of the individual State or Territory is divided by the apportionment quota.

Total population of individual State or Territory ÷ Quota = Number of Members

For example the calculation of the entitlement which triggered the 2003 redistribution in Queensland was:

3 729 123 ÷ 133 369.375 = 27.96086432

Applying the round up rule section 48 (2A) of the Act, Queensland was entitled to 28 seats, one additional seat.

Calculation of Malapportionment

Malapportionment occurs when an electorate contravenes the norm of equal representation according to the enrolment population. In effect, the value of votes in one or more electorate will differ from that in one or more other electorates. Malapportionment is possible only in electoral systems with more than one electoral constituency. Thus a proportional representation electoral system with only one national constituency like those in the Netherlands cannot be malapportioned.

Section 59 (10) of the Act states:

A reference in this section to a malapportioned Division is a reference to a Division in a State or the Australian Capital Territory in which the number of electors enrolled differs from the average divisional enrolment of the State or Territory to a greater extent than one-tenth more or one-tenth less.

In 1983 the Joint Standing Committee Inquiry assessed the degree of equality of Australia's electoral systems. Three measures of malapportionment were referred to in evidence. They were:

  • the David-Eisenberg Index
  • the Dauer-Kelsay Index
  • the Gini Index.

This report of the history of Australian redistributions cites all three indices. A detailed explanation of these indices appears in appendix one. A summary table containing population, enrolment and the three indices used is in appendix two.

Population Flux

In 2003, 3 redistribution processes commenced which resulted in 2 actual redistributions; Queensland and South Australia, and one revision; the Northern Territory. The Northern Territory did not undergo a Redistribution, but reverted to a single division as a result of the determination of entitlement made on 19 February 2003. The following tables show the population of Australia as required under the Act and the entitlement as a result of using the above formulae.

The Population[9]

The Population
State/Territory Number of people
New South Wales 6 657 478
Victoria 4 888 243
Queensland 3 729 123
Western Australia 1 934 508
South Australia 1 522 467
Tasmania 473 371
The Commonwealth[2] 19 205 190
The Australian Capital Territory[3] 322 871
Northern Territory[4] 199 760

The Entitlement

The number of Members of the House of Representatives to be chosen in each State and Territory is determined by dividing the number of people in each State and Territory by the apportionment quota, and rounding the result to the nearest whole number.

Entitlements by State/Territory
State/Territory Quotas Number of members to be chosen Change
New South Wales 49.9176 50 Nil
Victoria 36.6519 37 Nil
Queensland 27.9609 28 +1
Western Australia 14.5049 15 Nil
South Australia 11.4154 11 -1
Tasmania[5] 3.5493 5 Nil
Australian Capital Territory 2.4209 2 Nil
Northern Territory 1.4978 1 -1
Total   149 Nil

Explanatory Notes regarding calculation of Population and Entitlement

Under section 38A of the Act, the Territory of Norfolk Island is not taken to be a Territory for the purposes of the determination, but certain Norfolk Island residents are included in the State and ACT population figures.

Under section 45 of the Act, the total number of the people of the Commonwealth does not include the numbers of people of the Territories.

Under section 4 of the Act, the population figure for the ACT includes Jervis Bay for the purposes of the determination.

Under section 48 (2C) of the Act, the population figure of the Northern Territory includes Cocos (Keeling) Islands and Christmas Island for the purposes of the determination.

Under section 24 of the Constitution, Tasmania is guaranteed a minimum of five Members.

Enrolment Deviation

At the end of each month the Electoral Commissioner must ascertain the enrolment in each division, calculate the average divisional enrolment for each State and Territory, and determine the extent to which each division's enrolment deviates from the average divisional enrolment for the relevant State or Territory. These statistics must be published in the Government Gazette. The statistics constitute one method[10] of determining if a redistribution is required in a State or Territory

2 New South Wales, Victoria, Queensland and Western Australia had their initial boundaries decided by their respective state parliaments prior to Federation.

3 See Appendix Two for a summary of distributions and redistributions since federation.

4 See Appendix Three for the frequency of redistributions held since federation.

5 I C Harris (Ed) House of Representatives Practice 4th Edition (Canberra: Department of the House of Representatives 2001) p. 84.

6 ibid. p. 88.

7 Senate Brief No. 1 July 1999 Electing Australia's Senators at

8 Harry Evans (Ed.) Odgers' Australian Senate Practice Tenth Edition (Canberra; Department of the Senate, 2001) p. 123.

9 Commissioner Issues Federal Electoral Determination Attachment One Redistribution backgrounder 20 February 2003 at

10 A discussion of the triggers required to commence a redistribution are found on page 19

11 Gerard Newman and Andrew Kopras, 1999–2000 'Redistribution of Federal Electoral Boundaries' Current Issues Brief Number 3 2000–2001 Department of the Parliamentary Library at;fileType=application%2Fmsword