Just seven weeks out from a general election New Zealand's opposition Labour party has changed leaders.

Andrew Little resigned as leader of the Labour party yesterday — following a string of poor results in the polls and support for his party plummeting to just 23 per cent.

He's been replaced by 37-year-old Jacinda Ardern — she's promised to put the party's internal machinations to one side, and focus on winning the next month's election.