[6] 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.

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.

[20] 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."

[65] Following the 2005 election, NZ First entered into a confidence and supply agreement with the minority Labour government that also saw Peters appointed as Foreign Minister but not as a member of the Cabinet.

[71] On 20 October 2017, the names of Labour's 16 Cabinet ministers were announced as Jacinda Ardern, David Clark, Clare Curran, Kelvin Davis, Chris Hipkins, Iain Lees-Galloway, Andrew Little, Nanaia Mahuta, Stuart Nash, Damien O'Connor, David Parker, Grant Robertson, Jenny Salesa, Carmel Sepuloni, Phil Twyford, and Megan Woods.

[72] The Green Party announced on 21 October its three ministers outside cabinet and one parliamentary under-secretary slots as James Shaw, Julie Anne Genter, Jan Logie and Eugenie Sage.

On 25 October, it was announced that Ron Mark, Tracey Martin and Shane Jones would join the Cabinet, with Fletcher Tabuteau as a parliamentary under-secretary.

Only money from the broadcasting allocation can be used to purchase airtime; the actual production costs of advertisements can come from the general election expenses budget.

The Electoral Commission sets the amount of broadcasting funds each party gets; generally the allocation is based on the number of seats in the current Parliament, previous election results, and support in opinion polls.

[85] Labour leader Jacinda Ardern announced on 14 August 2017 that the party had reinstated a 2015 pledge to assist school students to learn to drive and budget.

[88] ACT leader David Seymour said on 2 September 2017 that the party would give schools $975 million more, so long as they abandon nationally negotiated union contracts.

Shaw said the fact that New Zealand was one of the only countries in the developed world without a consistent capital gains tax had helped fuel inequality between "those who don't own a home and those who now own ten".

The party said it would introduce a stricter test regime to ensure employers seek to hire New Zealanders before recruiting overseas applicants, and would require skilled migrants to stay and work in the region their visa was issued for.

[100] ACT wanted immigrants to "demonstrate they've earned above the average wage in their field" to get residency, and it would put an end to foreigners leaving their kids in New Zealand while paying taxes overseas by implementing an "infrastructure charge" of $10 per day for a maximum of a year for all migrants.

[103][104] On 21 August 2017, the party's leader Jacinda Ardern announced a $20 million plan for a passenger rail service linking Auckland, Hamilton and Tauranga.

The party would establish the line by 2027, and it could form the spine of an extended network north to Epuni via central Lower Hutt and south to Island Bay.

[109] At the same debate Labour leader Jacinda Ardern committed to changing the law to require that every government budget update would have to include a measurement of child poverty.

[115] On 12 July 2017, ACT deputy leader Beth Houlbrooke made a Facebook post criticising Labour's Best Start package, stating "The fact is, parents who cannot afford to have children should not be having them.

[117] National revealed the design of its first tranche of party hoardings in early July, featuring leader Bill English and the slogan "Delivering for New Zealanders".

Robertson's announcement reversed the position taken by leader Jacinda Ardern who had reserved the right to implement changes before obtaining a mandate at the 2020 election, and came as a Newshub-Reid Research poll showed National rising at the expense of Labour.

[136] On 7 August 2017,[137] MPs David Clendon and Kennedy Graham announced that they planned to resign as Green Party candidates for the 2017 election, due to Turei's revelations and her handling of the resulting situation.

[143] The party announced plans on 2 September 2017 to counter pollution by introducing a tax on farmers of $2 per kilogram of nitrate (fertiliser), which it said would raise about $136 million per year.

[144] Leader James Shaw said on 17 September 2017 that the party wanted a capital gains tax, exclusive of the family home, to be implemented in the first year after the election, if Labour and the Greens formed a coalition government.

Announced policies included ring-fencing GST to the regions it is collected from, writing off student loans of people willing to work outside major centres,[146] cutting net immigration to 10,000 per year, retaining the superannuation age at 65, and holding two binding referendums on whether Māori electorates should be abolished and whether the number of MPs should be reduced to 100.

[150] Peters had vowed in July that a Northport rail connection to Marsden Point at a cost of up to $1 billion was non-negotiable in any post–election coalition between NZ First and either National or Labour.

In previous elections their policies included improving public transport with fewer emissions, giving tax breaks to lower income earners, taking GST off food products, and banning the use of controversial 1080 poison.

[168] On 21 August 2017, United Future leader and sole MP Peter Dunne announced that he was quitting politics at the election, citing recent polling and his perception that there was a mood for change in his seat of Ōhāriu.

[169] United Future's candidate for the Botany electorate took over as leader shortly after, promising to move his party towards Labour because of its stance on social issues.

It was moderated by Fairfax's South Island editor-in-chief Joanna Norris and Stuff political editor Tracy Watkins, and was streamed online.

The six individuals are all charged with obtaining at least NZ$34,840 by deception or without claim of right, with the donation being paid to the Labour Party via an intermediary bank account.