Jacinda Ardern's partner took centre stage at Labour's campaign launch in Auckland today

Clark Gayford introduced the Prime Minister as his "not quite wife yet."

Ms Ardern says it's not the first time Clark's introduced her, saying he likes the chance to use new material.

Mr Gayford said it wasn't easy to win an argument with Ms Ardern, who's been voted the world's most eloquent leader.

She says he was right, it's not easy to win an argument with her.