Electoral redistributions during the 43rd Parliament

Research Paper no. 5 2010–11

Stephen Barber
Statistics and Mapping Section
8 October 2010


Redistribution provisions
Representation entitlement
Expiration of seven years
Deferral of redistribution


Executive Summary

  • The periodic redrawing of electoral boundaries is required by law to maintain electoral divisions of roughly equal enrolment size within a state or territory. Redrawing of boundaries is known as a redistribution.
  • During the expected life of the 43rd Parliament there will be redistributions in Victoria and South Australia because of the seven year provision in the Commonwealth Electoral Act 1918. The number of electoral divisions in these states will remain unchanged.
  • A redistribution of the Australian Capital Territory scheduled for later in the Parliament will be deferred until after the next election as it is scheduled to fall within 12 months of the deemed expiration of the House of Representatives.
  • There are not expected to be redistributions in any states or territories brought about by the representation entitlement trigger which determines the number of members a state or territory is entitled to in relation to its population.


Each state and territory is divided into electoral divisions for the House of Representatives. The number of divisions is determined by population and the Australian Constitution. The boundaries of these divisions have to be redrawn or redistributed from time to time to allow for population movements; thus ensuring equal representation between divisions within each state and territory.[1]

On 1 February 2010, the Australian Electoral Commission (AEC) directed the commencement of the redistribution of Commonwealth electoral boundaries in Victoria. This redistribution is one of only two redistributions that are expected to occur prior to the deemed expiration of this, the 43rd, Parliament. This paper outlines the reasons why.

Redistribution provisions

Section 59 of the Commonwealth Electoral Act 1918 (the Act) sets out the three provisions that trigger electoral redistributions.[2] Briefly, these are:

  • representation entitlement—a redistribution must be held if the number of members of the House of Representatives to which a state or territory is entitled changes
  • malapportioned divisions—a redistribution must be held if the number of electors in more than one third of the divisions in a state or territory deviates from the average enrolment in that state or territory by over 10 per cent for a period of more than two months (this has not been a trigger for a redistribution since the current provisions were introduced in 1984), and
  • expiration of seven years—if neither of the above provisions triggers a redistribution in a state or territory within seven years of the previous redistribution, then a redistribution must be held in that state or territory.

Representation entitlement

Under section 46 of the Act, the Electoral Commissioner ascertains the populations of the states and territories from the Australian Statistician the day after 12 months after the first meeting of a newly elected House of Representatives, provided that the ‘House of Representatives has continued for a period of 12 months’.[3] Section 48 of the Act specifies the manner in which representation entitlements are calculated from these population numbers.[4]

The first meeting of the new House of Representatives took place on 28 September 2010, so on 28 September 2011 the Electoral Commissioner will ascertain the latest population figures published by the Australian Bureau of Statistics (ABS).[5] According to the latest ABS publication of demographic statistics, the population figures that will be available at 28 September 2011 will relate to the end of December 2010.[6]

In order to estimate what these population figures might be, the Parliamentary Library has taken the most current population figures, March 2010, and projected these to December 2010 using the population growth figures for the period March 2009 to March 2010. The resultant estimated populations and representation entitlements of the states and territories are shown in Table 1.

Based on the estimates in the Table 1, all states and territories will easily retain their current representational entitlements. The sizes of their estimated quotas indicate that no state or territory is close to a situation of either losing or gaining an electoral division. Tasmania retains its five divisions, even though it would be entitled to only three under the representation entitlement formula, because section 24 of the Constitution guarantees that each of the original states is entitled to at least five members.

Table 1: Representational entitlements based upon March 2010 populations






Dec 2010



New South Wales

7 305 632





5 610 911





4 573 103




South Australia

1 656 706




Western Australia

2 325 505





 510 597




Six states (b)

21 982 454




Northern Territory (NT)

 231 725



Cocos (Keeling) Islands




Christmas Island

 1 454



   Total NT (c)

 233 784




Australian Capital Territory (ACT)

 362 583



Jervis Bay




   Total ACT (c)

 362 977





22 579 215




Note: For representational entitlement purposes, Cocos (Keeling) and Christmas Islands are included with the Northern Territory and Jervis Bay is included with the Australian Capital Territory.
(a)   Change over current entitlement.
(b)   The original states at the establishment of the Commonwealth of Australia. Section 24 of the Constitution entitles each original state to at least five members.
(c)   Section 48 of the Commonwealth Electoral Act 1918 allows for the addition of a margin of error to the population estimates of NT and ACT if it will affect the outcome of the entitlement. In this case the outcome is unchanged so the margin of error is not shown.

Expiration of seven years

Section 59 of the Act sets out that a redistribution in a state or territory must commence within 30 days of the expiration of seven years after the most recent redistribution in that state or territory (however, a redistribution can be deferred, see the next section). Table 2 sets out the dates of the most recent electoral redistributions held in each state and territory and the date of the next scheduled redistribution under this provision.

Under this provision, a redistribution of Victoria was commenced on 1 February 2010 with the final determination of boundaries scheduled for 17 December 2010.[7] Also, a redistribution of South Australia will commence in late December 2010 or early January 2011.

Table 2: Electoral redistribution dates due to expiration of seven years


Most recent

Next scheduled

New South Wales

22 December 2009

December 2016 / January 2017


17 December 2010 (a)

December 2017 / January 2018


15 December 2009

December 2016 / January 2017

South Australia

17 December 2003

December 2010 / January 2011

Western Australia

18 December 2008

December 2015 / January 2016


16 February 2009

February / March 2016

Northern Territory

19 September 2008

September / October 2015

Australian Capital Territory

9 December 2005

December 2012 / January 2013

(a) Scheduled date of determination of final boundaries. The current boundaries were determined on 29 January 2003

Deferral of redistribution

Under subsections 59(4) and 59(9) of the Act, redistributions scheduled within 12 months of the expiration of a House of Representatives are deferred and commence within 30 days after the first meeting of the new House of Representatives.

In recent times, this provision of the Act saw the redistribution of Tasmania, that was due to occur in March 2007 (as triggered by the seven-year rule), deferred until after the 2007 election. That redistribution commenced in February 2008.

A redistribution of the Australian Capital Territory (ACT) is scheduled for December 2012 or January 2013. However, with the first sitting of the 43rd Parliament occurring on 28 September 2010, the expiration of the Parliament is deemed to be 27 September 2013. This would mean that the redistribution scheduled for the ACT would be within 12 months of the expiration of the Parliament. It will, therefore, be deferred until after the next election provided this Parliament runs its full term.

The current redistribution of Victoria, although actually occurring within 12 months of an election, is taking place because it was due to commence in a period not entirely within 12 months from the deemed expiration date of the previous Parliament by effluxion of time. This date was 11 February 2011. Under the provisions of the Act, the redistribution had to start within 30 days after 29 January 2010. However, in reality, it needed to commence in the 13 day period from 29 January to 10 February 2010, because a direction to commence a redistribution cannot be made within 12 months of the deemed expiry date of the House of Representatives.[8]

An unfortunate complication of the Victorian redistribution process was caused when, on Saturday 17 July 2010, Prime Minister Julia Gillard announced her intention of holding an election on Saturday 21 August. This meant that under the redistribution timetable published in March 2010 (see footnote 6) the proposed redistributed boundaries for Victoria were announced during the election campaign (on Friday 30 July). Objections to these proposed boundaries then had to be lodged with the AEC by Friday 27 August—six days after the election—although there were a further 14 days to make comments on the objections lodged.

Under subsections 59(5) and 59(9A) of the Act, any redistribution due to occur during the first 13 months of the new Parliament will be deferred until after the representational entitlements determination is made if the Electoral Commission is of the opinion that the determination will alter the number of members.

The redistribution of South Australia which is due to commence soon should still proceed because, as shown in Table 1, South Australia is not expected to change its representational entitlements at the next determination.


A redistribution is already underway in Victoria and a redistribution of South Australia will commence in a few months. Neither of these redistributions will change the number of seats that these states are currently entitled to.

Population projections suggest that no redistributions are expected to be triggered by the representation entitlement determination 12 months after the first sitting of this Parliament.

The redistribution of the Australian Capital Territory, scheduled for the latter part of this Parliament and within 12 months of the expiry date of the House of Representatives, will be deferred until after the next election of the House of Representatives provided that this Parliament runs its full term.

The House of Representatives should go to the next election with an unchanged 150 electoral divisions.

[1].      Information on the redistribution process can be found on the Australian Electoral Commission website, Redistributions, accessed 29 September 2010.

[2].      Commonwealth Electoral Act 1918, accessed 29 September 2010.

[3].      Ibid., section 46(1). Note that the ‘day after 12 months’ is what we commonly think of as the anniversary date. For example, a calendar year starts on 1 January and finishes at midnight on 31 December; therefore, the ‘day after 12 months’ of a calendar year is 1 January of the next year.

[4].      An initial quota is ascertained by dividing the total population of the six states by twice the number of senators from the six states. A quota for each state and territory is then determined by dividing the population of the state or territory by the initial quota. The resultant figure rounded to the nearest whole number determines the entitlement.

[5].      The Electoral Commissioner adjusts ABS population estimates to include eligible Norfolk Island voters (see also sections 38A and 95AA of the Commonwealth Electoral Act 1918); as these adjustments are very small and do not affect the outcome, no estimates of these adjustments have been included in Table 1.

[6].      Australian Bureau of Statistics (ABS), Australian Demographic Statistics, March Quarter 2010, cat. no. 3101.0, ABS, Canberra, 2010, accessed 29 September 2010.

[7].      Australian Electoral Commission (AEC), Indicative timetable of 2010 Victorian redistribution, accessed 29 September 2010.

[8].       AEC, Announcement of 2010 Victorian redistribution, accessed 29 September 2010.


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