Under first-past-the-post (1853–1993) The electoral boundaries for the inaugural
1853 general election were drawn up by the
governor,
George Grey, with the authority for this coming from the
New Zealand Constitution Act 1852. After the initial election, there were eight redivisions carried out by members of the general assembly (as the lower house was known at the time). These revisions were a mixture of minor and major boundary adjustments. In 1887, the responsibility for reshaping electorates was given to a Representation Commission and that arrangement has remained to this day. Up until 1981, the boundaries of the Māori electorates were determined by the governor or governor-general, when that responsibility was also transferred to the Representation Commission. Since the Representation Act 1900 and 1902 electoral redistribution, the number of electorates had been fixed at 80. Slower growth in the population of the South Island compared to the North Island meant the number of South Island electorates, once near-equal to the North, was decreasing and the geographic size of those electorates was growing. The 80-electorate cap was removed in 1969 and instead the number of South Island electorates fixed at 25. Thereafter, the number of electorates steadily increased, peaking with 99 members elected in 1993, of whom 74 were elected from North Island electorates. Elections for the House of Representatives in the 1850s modelled the electoral procedures used for the
British House of Commons, which at that time featured both
single-member electorates (electorates returning just one MP) and
multi-member electorates (electorates returning more than one MP). Each electorate was allocated a different number of MPs (up to three) in order to balance electoral population differences. All electorates used a
plurality voting system, except
between 1908 and 1913 when a
two-round voting system was employed. Electorate boundaries were not always drawn to provide for proportional representation between communities. From 1881, a special
country quota meant that rural seats could contain fewer people than urban seats, preserving improportionality by over-representing the rural electoral population (mostly made up by farmers). The country quota inflated the number of the electoral population outside of cities and certain towns by some percentage. The quota was at first 33% (1881–1887), then briefly 18% (1887–1889), and 28% for the remaining period (1889–1945). For the
1905 election, the multi-member electorates were abolished. The country quota persisted until 1945. The new electoral system also provides for the number of Māori electorates to be calculated proportionally, and these have sat at 7 since 2002. In October 2024,
Statistics New Zealand announced that population changes necessitated reducing the number of North Island general electorates by one, returning the number of North Island general electorates to 48. Because the number of MPs is fixed at a minimum of 120, adding additional electorates means there are fewer seats available for
list MPs. List MP seats are assigned proportionally to parties that win at least one electorate or receive at least 5% of the
party vote. However, additional list MPs may be elected if
overhang seats are required due to a party winning more electorates than its party vote share entitles it; the total number of members may therefore be more than 120. In
2005 and
2011, 121 members were elected; 122 members were elected in
2008; 123 members were elected in
2023.
Representation Commission The Representation Commission has determined general electorate boundaries since 1881. These days, the Commission consists of: • Four government officials—the Government Statistician, the Surveyor-General, the Chief Electoral Officer, and the Chairperson of the Local Government Commission. • A representative of the governing party or coalition, and a representative of the opposition bloc. • A chairperson (often a judge) nominated by the other members (with the exception of Chairperson of the Local Government Commission). This quota is then used to calculate the number of
Māori electorates and to determine the number of
North Island electorates. The number of Māori electorates is calculated by dividing the
Māori electoral population (MEP) of New Zealand by the South Island Quota. Māori voters may choose to either be represented in a Māori electorate or a general electorate, so the MEP is influenced by the number of Māori who opt for Māori electorate representation. Māori voters who choose to be represented in a general electorate are included in the
General electoral population (GEP) of either the South Island or North Island. The number of North Island electorates is calculated by applying the South Island Quota to the North Island GEP. In this way, all three types of electorates will represent similar populations. Electorates may vary by no more than 5% of the average electoral population size. In drawing new electorate boundaries, the Representation Commission must give due consideration to existing boundaries, communities of interest, facilities of communications, topographical features, and projected variation in population. Regard is often had for
local authority boundaries. The Commission may abolish electorates and create new ones in their place. Except for Māori electorates, electorates must be wholly situated on either the North Island or South Island. Populations on other islands, such as
Stewart Island / Rakiura and the
Chatham Islands, are included by convention in electorates that provide access to the mainland, latterly
Invercargill and
Rongotai, respectively. ==Naming conventions==