[9][10] Ardern subsequently became the most successful New Zealand politician of the MMP era, overtaking John Key by number of seats won under a single premiership.

[11] With the election being highly centred around the government's praised response to the COVID-19 pandemic, it led to the unprecedented flipping of traditionally National-voting seats to Labour, often with very comfortable margins.

In a surprise victory, the left-wing environmentalist Green Party's Chlöe Swarbrick won the Auckland Central seat vacated by National's retiring Nikki Kaye with a margin of 1,068 votes over Labour's Helen White.

[15] The right-wing libertarian ACT Party and the Greens both increased their number of seats due to the collapse of National's support base.

The Māori Party, representing the cause of indigenous rights, re-entered Parliament with two seats after Rawiri Waititi won the Waiariki electorate.

Populist nationalist party New Zealand First, led by Deputy Prime Minister Winston Peters in coalition with Labour, suffered its worst-ever result, losing all its seats.

[18][19][20] Doing so alienated some left-wing Labour supporters, giving the Green Party a boost in seat numbers and their victory in Auckland Central.

[21] While results of opinion polls early in the year were neck-and-neck between the two major parties, Ardern and the Labour Government were praised for their response to the COVID-19 pandemic in New Zealand.

[22] In contrast, the leadership of the National Party changed twice in less than three months, unable to improve its poor polling results after collapsing in April 2020.

[23] Heading a campaign widely perceived as centrist or centre-leaning,[24][25] Labour gained support from a large demographic of moderate swing voters, many of whom had previously voted for National under John Key.

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."

Since the passage of the Electoral Amendment Act 2020,[48] which came into force on 11 March 2020, the writs must be returned within 60 days of their issuance (save for any judicial recount, death of a candidate, or emergency adjournment),[49] which would be 18 December 2020.

[62] On 17 July, National announced they would spend $31 billion on transport projects over the coming decade and would abolish the Auckland regional fuel tax.

[119] On 9 September, Finance spokesperson Grant Robertson announced that Labour would reintroduce the top 39% tax bracket for income above $180,000, applying to 2% of people.

This would be done by banning the building of new coal or gas power plants, boosting the solar sector, and speeding up the consent process for renewable energy projects.

[121] New Zealand First leader Winston Peters named the provincial growth fund in its current form as his first bottom line for any post-election coalition talks.

Green co-leader James Shaw described it as "a reference document that will guide our caucus and our ministers as we navigate the everyday choices that our Government will have to make.

ACT party leader David Seymour criticised the government's COVID-19 response as "clearly, demonstrably unsustainable", and called for the open pursuing of "having the world's smartest border, not as a rhetorical device, but a practical reality."

[160] Newshub Nation hosted a "power brokers" debate, which included the Māori Party, with the inclusion threshold being having held a seat in Parliament over the past 2 parliamentary terms.

[163][161][164] The requirements were modified on 8 September 2020, when TVNZ broadened their criteria to use previous parliamentary representation as a marker, including the Māori Party.

On 5 October 2020, The Spinoff reported that four EasyVote packs in Northland allegedly contained a flyer from Votesafe, a third-party promoter opposing the End of Life Choice Act.

[197] It is the first time under the current mixed-member proportional representation (MMP) electoral system that a party has won a majority of parliamentary seats.

[211] In another devastating blow to National's heartlands, every city except Auckland (including the Hibiscus Coast), Tauranga, Rotorua and Invercargill gave their seats entirely to Labour.

[220] Six new LGBT+ MPs were elected (Menéndez March, Glen Bennett, Ayesha Verrall, Shanan Halbert, Elizabeth Kerekere, Tangi Utikere), making the New Zealand House of Representatives the national parliament with the highest percentage of LGBT+ members in the world.

The following list candidates were elected: Andrew Little (07) David Parker (09) Trevor Mallard (11) Kris Faafoi (15) Ayesha Verrall (17) Willie Jackson (19) Louisa Wall (27) Camilla Belich (30) Jan Tinetti (32) Marja Lubeck (34) Angie Warren-Clark (35) Tāmati Coffey (37) Naisi Chen (38) Liz Craig (41) Ibrahim Omer (42) Anahila Kanongata'a-Suisuiki (44) Rachel Brooking (46) Helen White (48) Angela Roberts (50) Gerry Brownlee (02) Paul Goldsmith (03) Shane Reti (05) Chris Bishop (07) David Bennett (11) Michael Woodhouse (12) Nicola Willis (13) Melissa Lee (16) Nick Smith (18) Maureen Pugh (19) Marama Davidson (01) James Shaw (02) Julie Anne Genter (04) Jan Logie (05) Eugenie Sage (06) Golriz Ghahraman (07) Teanau Tuiono (08) Elizabeth Kerekere (09) Ricardo Menéndez March (10) Brooke van Velden (02) Nicole McKee (03) Chris Baillie (04) Simon Court (05) James McDowall (06) Karen Chhour (07) Mark Cameron (08) Toni Severin (09) Damien Smith (10) Debbie Ngarewa-Packer (01) On 31 October, Ardern announced that despite the Labour Party having won enough seats to continue the Sixth Labour Government on their own, they had invited the Greens to participate in a "cooperation agreement", seeking their input on matters such as the environment, climate change and child wellbeing, and that the Greens had accepted the offer.

[241][242] On 12 April 2021, the Electoral Commission referred the Māori Party to the Police for failing to disclose about NZ$320,000 worth of donations within the required timeframe.

[246][247][248] In late April 2021, the Electoral Commission issued the National Party with a warning for failing to declare a NZ$35,000 donation from real estate mogul Garth Barfoot but declined to refer the matter to the police.

In late May 2021, Rangitīkei candidate Ricky Cribb pleaded guilty to two charges of violating the Electoral Act 1993 and was fined $300 plus court costs.

[251] In early July, Advance NZ Invercargill candidate Kurt Rohloff had his Electoral Act charge for failing to declare election and donation returns dismissed after completing a diversion.

[254] In September 2021, former Public Party leader and Advance NZ co-leader Billy Te Kahika was charged with filing a false electoral donation and obtaining $15,000 by deception.