When are electorates reviewed?

New Zealand's electorate boundaries must be redrawn by the Representation Commission after each five-yearly population census and Maori Electoral Option. The Representation Commission was last convened in 2007 to redraw the electorate boundaries for the 2008 and 2011 general elections.

Why do electorate boundaries need to be reviewed?

Under the Electoral Act, electorate boundaries must be redrawn after each five-yearly population census and Māori Electoral Option. This is to ensure the number of people in each electorate reflects changes in population and that electorate names remain relevant.

As a consequence of changes to the population since the last population census, approximately half of existing electorates are either over or under-populated and many changes to boundaries will result.

What impact do Representation Commission decisions have?

The Representation Commission determines where the boundaries of electorates are located.  In doing so, the Commission must ensure that the electoral population for each electorate is within +/- 5% of the population quota for that electorate.

For some voters, a change to the boundaries may mean that the electorate a voter lives in changes. If so, the voter may find that the candidates standing to become members of Parliament in their new electorate may be different to the candidates standing in their previous electorate.

The Representation Commission also needs to ensure that the names of electorates are current and reflect the communities within them. For the voter, this may mean that the name of their electorate changes, even if they are not affected by changes to boundaries.

Who makes decisions on names and boundaries of electorates?

The Representation Commission is an independent statutory body that reviews and redraws New Zealand’s electorate boundaries every five years.  Membership of the Representation Commission is specified in legislation. It includes four ex officio members (the Surveyor-General, the Government Statistician, the Chief Electoral Officer, and the Chairperson of the Local Government Commission) and two political representatives appointed by the Governor-General on the nomination of the House of Representatives, one to represent the Government and one to represent the Opposition.

The Chairperson of the Representation Commission is appointed by the Governor-General on the nomination of the Commission. By convention the Chairperson is usually a district court judge.

When considering the boundaries of the Māori electorates, the Representation Commission membership includes the chief executive of Te Puni Kōkiri and two political representatives who must be Māori. These political representatives are appointed by the Governor-General on the nomination of the House of Representatives, one representing the Government and one representing the Opposition. 

How is the number of electorates decided?

Electoral districts must have similar numbers of people living in them, regardless of the geographic area an electorate covers.  The Government Statistician calculates the electoral population of all electorates. 

Under legislation, there is always 16 South Island general electorates.  The population quota for each South Island general electorate is calculated by dividing the population of the South Island by 16. 

In 2007 the calculation was:

920,999	= 57,562 South Island general electorate population quota.
16

Because all electorates are required to be of a similar size, the number of Māori electorates and North Island electorates are calculated by dividing the relevant electoral populations by the South Island quota. 

In 2007 the calculations were:

Māori electorates

417,081	= 7.25 rounded to 7 Māori electorates.
57,562

North Island electorates

2,690,437	= 46.74 rounded to 47 North Island general electorates.
57,562

7 Māori electorates + 47 North Island electorates + 16 South Island electorates + 50 list members of Parliament = 120 members of Parliament.

How are decisions made about where to draw the electorate boundaries?

Each electorate must have an electoral population that is within +/- 5 percent of its electoral population quota.

The Representation Commission decides the electorate boundaries using the following criteria:

• existing electorate boundaries
• community of interest – including tribal affiliations for Māori electorates
• communications facilities – including links such as roads and telephone services
• topographical features – such as mountains and rivers
• projected variations in electoral populations – particularly large regional changes expected within five years.

In respect of Māori electorates, the Representation Commission uses the above criteria and also takes into account tribal affiliations when deciding the electorate boundaries.

Can the public have a say on the proposed electorate boundaries?

The public can make objections and counter-objections to the proposed names and boundaries as part of the Representation Commission's public consultation process.

People can make written objections to the proposed boundaries or suggest alternatives. These boundary objections will be summarised and published.

The public then has two weeks to make counter-objections to any objection received for the proposed boundaries.

The Representation Commission will meet to hear the objections and counter-objections before making final decisions.

Final electoral boundaries

The Representation Commission produces its final report on the names and boundaries of electorates after considering any objections and counter-objections. The Commission publishes a notice, stating that it has determined the electorate names and boundaries and where this information can be found. These become the electorates for general elections until the Commission reviews them again.