Prime Minister Jacinda Ardern reveals September 19 election date

Prime Minister Jacinda Ardern has announced the general election will be held on September 19.

Speaking to reporters at the year's first post-cabinet press conference, Ardern said she believed the now-common practice of announcing elections early in the year was fair.

The date means Parliament will sit for the last time on August 6 and will be officially dissolved on August 12.

"Until then the Government will continue on getting things done," Ardern said, reiterating an earlier pledge to run a "positive, factual and robust election campaign".

Asked whether the All Blacks fixtures for the year had factored into picking the election date, Ardern said things that could distract voters had been on her mind, along with other factors such as school and public holidays.

Much of Parliament will be heading to Waitangi next week, and Parliament is due to resume the following week where the Government parties and National Opposition will face off.

The last election was September 23, 2017 and the last possible date for an election this year is November 21.

New Zealand First is understood to have favoured a November election date while Labour and the Greens favoured an earlier one that will make it easier to mobilise tertiary students.

While Ardern leads a Labour-New Zealand Coalition Government, setting the election date has always been the prerogative of the Prime Minister.

The consent of a coalition partner is not required.

New Zealand First held the balance of power after the 2017 election and after parallel negotiations with Labour and National, chose to go with Labour, supported by the Greens, despite National being the largest party.