New Zealand is a constitutional monarchy and parliamentary democracy, with Queen Elizabeth II titular head of state, represented in the country by the Governor-General.
There is a unicameral House of Representatives, directly elected for a three-year term, with universal suffrage for everyone over 18. Voting is not compulsory, though enrolment is. The number of MPs rose from 99 to 120 in 1996, under the new electoral system when the country moved to a form of proportional representation known as MMP (mixed member proportional). Voters have an electorate vote and a party vote. The former is used to select an MP in 70 constituencies – including seven Maori constituencies – on a first-past-the-post basis, while the latter is used to select a party and determine the total number of seats for each party in parliament. All parties polling more than five per cent of this vote (or with at least one electorate seat) are entitled to further seats based on the proportion of the party votes cast. Normally 50 members are party MPs but this number can be increased (increasing the total number of seats in parliament for the term) when a party wins more electorate seats than it is entitled to according to the party vote. This happened for the first time in September 2005, when there was a single Maori Party ‘overhang’ MP.
The Prime Minister is appointed by the Governor-General on the basis of party strength in the House of Representatives and the Prime Minister appoints a cabinet.
The MMP system is designed to prevent domination by a majority group and to give voice to minorities, under-represented in Westminster (first-past-the-post) systems. It is also intended to encourage voting on the basis of policies rather than a party bloc. In the first election under MMP, the proportion of women MPs rose by half to about one-third of the total and the Maori community obtained representation to match its 13 per cent share in the population.
In the general election of November 1999 the Labour Party, led by Helen Clark, won 49 seats and its coalition partner Alliance ten. The National Party, led by Jenny Shipley, took 39 seats and its ally, the Association of Consumers and Taxpayers of New Zealand (ACT New Zealand), nine. With the support of the Green Party (seven seats), Labour was able to command a majority in the 120-member House of Representatives and Helen Clark became Prime Minister.
In the July 2002 general election, Labour (52 seats) and its coalition partner – Progressive Coalition Party (two) – were unable to command a parliamentary majority without the support of smaller parties. These now included United Future (eight) and the Green Party (nine). The National Party secured 27 seats and ACT New Zealand nine, while its former coalition partner, New Zealand First, strengthened its position to 13.
The September 2005 general election was very close, but when all the votes were counted, the ruling Labour–Progressive coalition (Labour 50 seats, Progressive one) was returned for a third successive term and Helen Clark continued as Prime Minister, still able to command a majority in parliament only with support from New Zealand First (seven) and United Future Party (three). The National Party won 48 seats and the Green Party six.
The National Party – under the leadership of John Key – won the November 2008 election with 58 seats and 44.9 per cent of votes, and like previous governments would only be able to command a majority in the House with support from minority parties. Turnout was 79.5 per cent and Labour took 43 seats (34.0 per cent of votes), Green Party nine, ACT New Zealand five, the Maori Party five, Jim Anderton’s Progressive one, United Future one and New Zealand First none.
In the November 2011 election the National Party increased its share of votes to 47.3 per cent, though with 59 seats still short of an absolute majority in parliament. Labour took 34 seats (27.5 per cent), the Green Party 14 (11.1 per cent), New Zealand First eight (6.6 per cent) and the Maori Party three. ACT New Zealand, Mana and United Future each won one seat. With the support of ACT and United Future, John Key was sworn in as Prime Minister for a second time. In December 2011 the National Party formed a coalition government with ACT New Zealand, United Future and the Maori Party.
The National Party won the election held on 20 September 2014, with 47.0 per cent of the vote and 60 seats, just short of an outright majority. The Labour Party received 25.1 per cent of the vote (32 seats); the Green Party 10.7 per cent (14); and New Zealand First 8.7 per cent (11). The Maori Party, ACT and United Future each won an ‘electorate’ seat. But United Future’s party vote did not entitle it to any seats, so its electorate seat was an ‘overhang’ seat, bringing the total number of members in the new parliament to 121. John Key reached ‘confidence and supply’ agreements with the three smaller parties and formed a new government.
The 2017 New Zealand general election took place on Saturday 23 September 2017 to determine the membership of the 52nd New Zealand Parliament. The previous parliament was elected on 20 September 2014 and was officially dissolved on 22 August 2017. Voters elected 120 members to the House of Representatives under New Zealand's mixed-member proportional (MMP) voting system, a proportional representation system in which 71 members were elected from single-member electorates and 49 members were elected from closed party lists. Around 3.57 million people were registered to vote in the election, with 2.63 million (79.8%) turning out. Advance voting proved popular, with 1.24 million votes cast before election day, more than the previous two elections combined.