It's Labour ... and Prime Minister Jacinda Ardern.

New Zealand First has crowned Ardern the next prime minister with its decision to back a Labour-led government, which will also need the Green Party to govern.

Ardern will claim the top job after only two and a-half months as Labour leader - and follows her former mentor Helen Clark into the top job. 

The decision will come as a shock to National, which holds two more seats than the Labour-Green bloc and ends its hope of leading New Zealand for a fourth term.

WATCH THE FULL ANNOUNCEMENT ABOVE