The Prime Minister is being urged to show leadership over a deepening sexual assault saga.
Jacinda Ardern and the president of the Labour Party say they didn't know allegations against a staffer were of a sexual nature.
But National Party MP Mark Mitchell says the party has a massive cultural issue with the way it treats women.
He says culture is driven by leadership and the PM can't hide behind the veil of deniability.
But Labour's Stuart Nash says Ardern will get to the bottom of this, because it cuts to the heart of what it means to be in the party.
He says he completely believes the PM because she doesn't lie or bend the truth.