The Australian Bureau of Statistics (ABS) has released state population figures this morning that confirm a change in seat numbers for three states at the next Federal election.
New South Wales representation will be reduced from 47 to 46 seats, Victoria reduced from 39 to 38 seats, while Western Australia will gain a seat, increasing from 15 to 16 seats.
Other jurisdictions remain unchanged, Queensland with 30 seats, South Australia 10, Tasmania five, Australian Capital Territory three and Northern Territory two.
The next election will be for a 150 member House of Representatives, down one from the current 151 seats.
The current elected members per state remain unchanged until the next election, due between August 2024 and May 2025. Redistributions will take place in the three affected states to bring the number of electoral divisions in line with the change in allocated members.
The change in numbers will become official in the last week of July, one year after the first sitting of the current House of Representatives, when the Australian Electoral Commissioner Tom Rogers issues a formal determination of House representation by state and territory.
Commissioner Rogers has no personal choice in making the determination as the method is strictly defined in law. For states the Commissioner will apply the formula set out in Section 24 of the Constitution. For the Territories the Commissioner will use the formula set out in the Electoral Act. The Constitution also states that the Commissioner will use the “latest statistics of the Commonwealth”, a phrase the High Court and Parliament has determined will be the quarterly population statistics, that is today’s ABS release.
The precise calculations around how seats are allocated is explained inside this post.
Once the new numbers are officially announced at the end of July, redistributions to implement the changed seat numbers will get underway in NSW, Victoria and Western Australia. Based on past redistribution timelines, the process of drawing new boundaries should be completed by early July 2024, in time for use at the next election.
The changes in Victoria and Western Australia reverse changed numbers that first applied at the 2022 election.
For NSW, the reduction to 46 continues a long term trend. When the parliament was increased in size in 1984, 51 of the 148 seats were in NSW. The state lost seats at the 1993, 2007, 2010 and 2016 elections.
The latest changes have come about because of changes in relative state populations. The populations of NSW and Victoria have been growing more slowly than other state, meaning both states declined relative to other states. In large part this has come about because of the two year halt to immigration, ending the usual large migrant inflow to the nation’s two largest states. Despite closing its state border in the same period, over three full years Western Australia has been a beneficiary of internal migration from other states.
How the Determination is made
Under Section 24 of the Constitution, the following calculations are undertaken to allocate members and seats to states.
First the Commissioner uses the ABS statistics to determine the population of the Commonwealth. An important point here is the the High Court has ruled that the population of the Commonwealth is the population of the states, that is excluding the Territories.
The Constitution then specifies that a quota be calculated by dividing the population of the Commonwealth by twice the number of Senators. The High Court has also ruled on this provision and the divisor is twice the number of State Senators. The four Territory Senators are ignored, the number of State Senators is 72 so the divisor is 144.
Based on today’s ABS report, the quota is 25,552,408 divided by 144 which equals 177,447.277780
The population of each state and territory is then divided by the quota, the resultant quotient determining the number of members each jurisdiction will be allocated.
The Constitution sets out the following rules for allocating seats to states –
- A number of seats equal to the whole number part of the quotient is allocated to each state.
- If the fractional part of the quotient is greater than 0.5, the state is allocated an extra seat.
- Notwithstanding the above calculations, all original states are entitled to five seats. That’s why Tasmania retains five House seats.
Allocation of seats to Territories is determined by the Electoral Act rather than the Constitution. Before the 2022 election, the Commonwealth Parliament altered the formula for territories so the following rules apply to the quotient of each territory –
- A number of seats equal to the whole number part of the quotient is allocated to each territory.
- If the quotient is greater than two and less than three, then if the fractional part of the quotient is greater than 0.4, then the territory is allocated an extra seat. (This rules currently applies to the ACT.)
- If the quotient is greater than one and less than two, then if the fractional part of the quotient is greater than 0.333333, then the territory is allocated an extra seat. (This rules currently applies to the NT.)
The Calculation Table
All the calculations that apply to the current determination are set out below. (Try turning your screen 90 degrees if you are on a mobile)
|New South Wales||8,238,801||46.42957110||46||..||46||-1|
|Australian Capital Territory||460,855||2.59713762||2||1||3||..|
Source: ABS national, state and territory population statistics.
Note: Around 5,000 voters in other territories are not included in above table. Norfolk island and Jervis Bay will be added to the ACT. Christmas and Cocos Keeling Islands are added to the Northern Territory.
The above changes will result in the current 151 member House of Representatives being reduced to 150 at the next election.
All current members and seats remain in place until writs are issued for the next election. Over the next year, the three states with changed representation will undergo redistributions to draw boundaries for a number of electorate equal to the new number of members to be elected.
The chart below shows the seats per state and territory at elections since the House and Senate were increased in size at the 1984 election.