"We will be asking for a further term to get the job done," the Prime Minister said at her post-Cabinet press conference on Tuesday, after confirming the date.

New Zealand operates under a mixed-member proportional (MMP) voting system. In 2017, 71 members were elected from single-member electorates and 49 members were elected from closed party lists.

In September last year, it was announced there will be a new electorate at the 2020 general election resulting in one fewer list seats in Parliament than at the 2017 election.

The 2017 election saw five political parties return to Parliament - National, Labour, New Zealand First, the Greens and ACT - down from seven parties in 2014.

One of those parties that didn't make it back to Parliament was the Māori Party, and it's rumoured they are gearing up for a return to Parliament in 2020.

After the 2017 election, even with support partner ACT, the National Party were short of the 61 seats needed to govern following the 2017 general election results.

It needed New Zealand First's nine seats to govern, but New Zealand First leader Winston Peters decided to give his seats to Labour and form a coalition, with the Greens as Labour's confidence and supply partner.

The election resulted in Labour leader Jacinda Ardern becoming New Zealand's third female Prime Minister, and Peters taking on the Deputy Prime Minister role for a second time.