National Party leader Simon Bridges' leadership may be in question as outgoing National MP Jami-Lee Ross is expected to take recorded conversations to police today, which Mr Ross says proves he broke electoral law.
"It really depends how this plays out today with this police investigation," Mutch McKay said.
"I think it's fair to say that there are questions about how secure and how sure his leadership is."
She said Mr Bridges is "very keen to paint the picture that it is a 'lone wolf' - that he is acting alone".
"Jami-Lee Ross says that's not the case, that there are other people in the party who feel the same way as he did and they're just too nervous to speak up.
"Don't forget – this is his right-hand man. They were close friends, they were allies, he helped elect him into power, so to have someone like that turn, that's not a good thing in the party."
Mr Ross says the recording will be made public after he has gone to the police.