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.
Prior to the election, the centre-right National Party, led by Prime Minister Bill English, had governed since 2008 in a minority government with confidence and supply from the Māori, ACT and United Future parties. It was the first election for English as incumbent prime minister, having replaced John Key on 12 December 2016 and the first since 1975 where both major parties had leadership changes. The main opposition parties to the National government were Labour (the official opposition), led by Jacinda Ardern, the Green Party, and New Zealand First.
The National Party won a plurality of the seats with 56, down from 60 in 2014. Labour made large gains following Jacinda Ardern becoming the party leader seven weeks prior to the election, increasing its representation from 32 to 46 seats. Labour was the only parliamentary party to gain support but a large portion came at the expense of the Green Party, who lost almost half their seats (dropping from 14 to 8) following co-leader Metiria Turei's resignation over self-admitted historical benefit and electoral fraud. The anti-immigration populist party New Zealand First won 9 seats, down from 12 in 2014. ACT retained its one seat. Election-night counts had National with 58 seats, Labour with 45 seats, and the Greens with 7 seats, but when special votes were counted, National lost one list seat each to the Greens and Labour.
The election saw five parties return to Parliament, down from seven in 2014 and the lowest number since the introduction of MMP in 1996. Māori Party co-leader Te Ururoa Flavell lost his seat of Waiariki and, with the party's vote count being below the threshold of 5%, they also lost their list MP, co-leader Marama Fox, and departed Parliament. United Future leader and sole MP Peter Dunne retired from politics during the campaign due to poor polling in his electorate of Ōhāriu and his successor failed to win the seat. The party voted to dissolve less than two months later.
Even with support partner ACT retaining its sole seat, the existing National minority government were short of the 61 seats needed to govern, and Bill English declared that the arrangement would not be continued. New Zealand First's nine seats gave it the balance of power between the National Party and the Labour–Green bloc. On 19 October 2017, New Zealand First leader Winston Peters announced that the party was intending to form a minority coalition government with the Labour Party of 55 seats, with confidence and supply agreement from the Green Party. This is the first Government in New Zealand under MMP where the most popular party is not part of the Government. The election resulted in Ardern becoming New Zealand's third female prime minister, and Peters being reappointed deputy prime minister, a role he had first held in 1996–98. This marked an end to nine years under the Fifth National Government, and the beginning of the Sixth Labour Government of New Zealand.
Electoral system.
New Zealand uses the mixed-member proportional (MMP) voting system to elect the 120-member House of Representatives. Each voter gets two votes, one for a political party (the party vote) and one for a local candidate (the electorate vote). Political parties which meet the threshold (5% of the party vote or one electorate seat) receive seats in the House in proportion to the percentage of the party vote they receive. In the 2014 and 2017 elections, 71 of the 120 seats were filled by the MPs elected from the electorates, with the winner in each electorate determined by the plurality ("first-past-the-post") method; the remaining 49 seats were filled by candidates from each party's closed party list. If a party wins more electorates than seats it is entitled to under the party vote, an overhang results; in this case, the House will add extra seats to cover the overhang. The 2014 election saw a one-seat overhang where Peter Dunne won the Ōhāriu electorate when his United Future Party was entitled to zero seats under the party vote.
The majority of members in the House will form a Government. Since it is difficult for any single party to win a majority of seats under MMP, parties must generally negotiate with other parties either to form a majority coalition government or to obtain sufficient confidence and supply to operate as a minority government.
Electorate boundaries in the 2017 election were the same as at the 2014 election, with 64 general electorates (48 in the North Island and 16 in the South Island), and 7 Māori electorates.
Electoral law changes.
The Electoral Amendment Act 2017 and the Broadcasting (Election Programmes and Election Advertising) Amendment Act 2017 made a number of changes to the conduct of general elections, including:
Eligibility to vote.
To vote in the general election, one must:
Election schedule.
Unless an early election is called or the election date is set to circumvent holding a by-election, a general election is held every three years. The previous election was held on Saturday, 20 September 2014.
The Governor-General must issue writs for an election within seven days of the expiration or dissolution of the current Parliament. Under section 17 of the Constitution Act 1986, Parliament expires three years "from the day fixed for the return of the writs issued for the last preceding general election of members of the House of Representatives, and no longer." The writs for the 2014 election were returned on 10 October 2014, a day late due to a judicial recount of the Te Tai Tokerau electorate. As a result, the 51st Parliament would have expired, if not dissolved earlier, on Tuesday, 10 October 2017. Consequently, the last day for issuance of writs of election would have been 17 October 2017. The writs must be returned within 50 days of their issuance (save for any judicial recount or death of a candidate), which would have been Wednesday, 6 December 2017. Because polling day must be a Saturday and two weeks is generally required for the counting of special votes, the last possible date for the 2017 general election would have been Saturday, 18 November 2017.
On 1 February 2017, Prime Minister Bill English announced that the election would be held on Saturday 23 September 2017. This was the first election since 1975 that both major parties, Labour and National, contested under new leadership.
Key dates relating to the general election were as follows.
Parties and candidates.
Political parties registered with the Electoral Commission can contest the general election as a party. To register, parties must have at least 500 financial members, an auditor, and an appropriate party name. A registered party may submit a party list to contest the party vote, and can have a party campaign expenses limit in addition to limits on individual candidates' campaigns. Unregistered parties and independents can contest the electorate vote only.
The following registered parties contested the general election:
MPs who did not stand for re-election.
Twenty-two members of parliament announced that they would not stand for re-election.
Results.
Preliminary results were gradually released after polling booths closed at 19:00 (NZST) on 23 September. The preliminary count only includes advance ordinary and election day ordinary votes; it does not include any special votes. Special votes include votes from those who enrolled after the deadline of 23 August, those who voted outside their electorate (this includes all overseas votes), hospital votes, and those voters enrolled on the unpublished roll.
All voting papers, counterfoils and electoral rolls are returned to the electorate's returning officer for a mandatory recount; this also includes approving and counting any special votes, and compiling a master roll to ensure no voter has voted more than once. Official results, including all recounted ordinary votes and special votes, were released by the Electoral Commission on Saturday 7 October 2017.
Parties and candidates have three working days after the release of the official results to apply for a judicial recount. These recounts take place under the auspices of a District Court judge (the Chief District Court Judge in case of a nationwide recount), and may delay the return of the election writ by a few days.
Party vote percentage
 ;templatestyles src="Legend/styles.css" / ;  National
 (44.45%) ;templatestyles src="Legend/styles.css" / ;  Labour
 (36.89%) ;templatestyles src="Legend/styles.css" / ;  NZ First
 (7.20%) ;templatestyles src="Legend/styles.css" / ;  Green
 (6.27%) ;templatestyles src="Legend/styles.css" / ;  Opportunities
 (2.44%) ;templatestyles src="Legend/styles.css" / ;  Māori
 (1.18%) ;templatestyles src="Legend/styles.css" / ;  ACT
 (0.50%) ;templatestyles src="Legend/styles.css" / ;  Legalise Cannabis
 (0.31%) ;templatestyles src="Legend/styles.css" / ;  Conservative
 (0.24%) ;templatestyles src="Legend/styles.css" / ;  Other (0.5199999999999978%)
Electorate results.
Prior to the election, the National Party held the majority of the electorate seats with 40. Labour held 27 seats, and NZ First, ACT, and United Future held one seat each. Between the 2014 and 2017 elections, one seat changed allegiance: in the 2015 Northland by-election, NZ First leader Winston Peters won the seat off National, after MP Mike Sabin resigned.
Fifty-five electorates saw the incumbent MP re-elected, while another 11 saw a new MP elected from the same party as the retiring incumbent.
In three electorates, the incumbent MP was defeated. Labour candidate and lawyer Duncan Webb claimed Christchurch Central off National MP Nicky Wagner; Labour previously held the electorate continuously from its formation in 1946 until Wagner won it in 2011. After National lost Northland to NZ First leader Winston Peters in 2015, candidate Matt King claimed the electorate back for National from Peters. Labour candidate and former television presenter Tāmati Coffey claimed Waiariki off Māori Party MP Te Ururoa Flavell; Flavell's defeat saw the Māori Party without an electorate seat and with the party polling below 5% in the party vote, saw the party voted out of Parliament. Coffey's win also saw Labour claim a clean sweep of the Māori electorates for the first time since the 2002 election.
In Hutt South, National list MP Chris Bishop claimed the electorate from Labour – the first time the electorate has swung since its creation in 1996. Contributing to the swing was the 2014 boundary changes which saw the Labour-leaning suburb of Naenae swapped for the National-leaning western hill suburbs of Lower Hutt, and long standing Labour MP Trevor Mallard standing down at the election to contest the party list only. In Ōhāriu, incumbent United Future MP Peter Dunne stepped down after holding the electorate in various incarnations since 1984. Labour candidate and former police officer Greg O'Connor subsequently claimed the electorate.
Overall, National gained one electorate to hold 41, Labour gained two electorates to hold 29, while ACT retained its one electorate seat.
Hamilton West was considered to be New Zealand's bellwether seat. Since the formation of the electorate in 1969, the winning candidate was from the party that went on to form the government, with the exception of 1993 when it elected a Labour MP while National went on to form the government (albeit with a one-seat majority). Hamilton West, Maungakiekie and Rotorua were also regarded as bellwethers in the MMP era, swinging with the government at every election since 1996. All three electorates in the 2017 election were won by National candidates.
List results.
The following MPs were elected from their respective party lists:
Changes in MPs.
Two former MPs (Shane Jones and Willie Jackson) and 31 first-time MPs were elected to the 52nd Parliament, joining 87 incumbents from the 51st Parliament.
Following the retirement of Peter Dunne, Bill English (National, list) became the new Father of the House, having served as an MP continuously since 1990. While both Winston Peters and Trevor Mallard have served longer than English, their tenures have been non-continuous.
23-year-old Chlöe Swarbrick (Green, list) became the new Baby of the House. She was the youngest MP to be elected to Parliament since the election of the 23-year-old Marilyn Waring in 1975.
Golriz Ghahraman (Green, list) became the first former refugee to be elected to the New Zealand Parliament.
Government formation.
Preliminary election results gave National 58 seats,