Paula Bennett is calling for Winston Peters to be stood down as Deputy Prime Minister for what she is deeming "unethical behaviour".
The National Party deputy leader also said the Prime Minister is "running scared", criticising her for not taking action against the NZ First leader.
Her comments come as the Serious Fraud Office investigates donations made to the New Zealand First foundation, and allegations that Mr Peters had journalists followed and photographed over their reporting on the investigation.
Jacinda Ardern told TVNZ1's Breakfast today she doesn't want to "get in front of decisions made by the independent agency" and that "party leaders need to be responsible for their own management of their political parties".
But Ms Bennett told media today that the Prime Minister should be asking questions.
"Why did he say we took the photos and then retract 24 hours later," she says.
"I think she's running scared that he may pull the plug and I don't think they're ready for an early election."
By not asking any questions, Ms Bennett says she thinks Ms Ardern is "supporting that behaviour".
"The manual is very clear, the cabinet manual, that a minister must uphold the highest ethical standards," she says.
"By Jacinda Ardern choosing a see no evil hear no evil approach to this, she is in many ways I think is supporting this kind of unethical behaviour."