Paula Bennett is not convinced Jacinda Ardern did not know about sexual assault claims raised against a Labour staffer, and is telling the PM to "step up".
"From what I could hear this morning, she's still saying that her senior staff didn't know," National's deputy leader said, pointing to comments Ardern made Thursday morning.
"Well, if senior staff didn't know, why was the alleged perpetrator stood down five weeks ago? It certainly wasn't for anything other than allegations of sexual assault."
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The alleged attacker is understood to have been working away from Parliament.
The Prime Minister said on Monday he hadn't used his Parliament access pass since allegations were raised by Newshub about five weeks ago.
Newshub's political editor Tova O'Brien broke a story on August 5 that Labour had been forced to review an internal investigation into bullying, sexual harassment and sexual assault by a party staffer.
The Prime Minister maintains she did not know that sexual assault allegations had been raised, because members of the Labour panel who heard testimonies from alleged victims said that aspect wasn't disclosed.
That's despite emails seen by Newshub that show Labour was sent details six months ago of sexual assault allegations against a party staffer.
Bennett said she is confident Ardern "absolutely knew there were sexual assault allegations against one of her staff members".
Bennett named senior Labour members in Parliament on Wednesday, including the PM's former chief of staff Mike Munro, alleging they knew about the sexual assault claims.
Complainants have told Newshub that Finance Minister Grant Robertson was told in person about the sexual assault allegations on 30 June at an event where the PM was also present.
Robertson said he's "simply not going into it".
Bennett said: "It goes right to the heart of the kind of leadership that [Ardern] wanted to display, and that a lot of young women believed in her for.
"She has absolutely let [the alleged victims] down and they want to see her step up now and take responsibility. She needs to bring in sexual violence specialists.
"They deserve now to have specialist support here managing this process."
Ardern claims she became aware of the sexual assault allegations when The Spinoff ran a story on Monday that detailed the alleged assault.
The debacle led to the resignation of Labour Party President Nigel Haworth on Wednesday.
Bennett also took aim at Green MP and Minister for Women Julie Anne Genter in Parliament on Thursday, asking her how victims in these situations should handle it.
"I do think it is important that if it is the wishes of the complainants in the case that it should be reported to the relevant manager," Genter replied.
"Bullying, sexual harassment, sexual assault are all very serious problems right across society, no institution is immune from them, the Francis Review has shown that in Parliament."
"We all have a responsibility to make sure that women are safe and that there are victim-centred enquiries into these matters."