"Let's do this" - that's the slogan Labour hopes will win it the election.

New leader Jacinda Ardern unveiled the phrase on Friday with a new campaign video featuring just her, replacing the previous "fresh approach" tagline.

Ms Ardern will feature alone on new campaign billboards, rather than alongside her deputy leader Kelvin Davis.

Instead he says he's going to sit back and bask in the "Jacinda glow".

On what the new slogan means, Ms Ardern said it's simply that "we've got seven weeks to change the government".

Labour has also recruited former prime minister Helen Clark's former chief press secretary Mike Munro as a strategist.

He worked for Wellington Mayor Justin Lester during his election run last year.