National leader Judith Collins says she would not have sacked Iain Lees-Galloway and is accusing the Prime Minister of having prior knowledge of his affair - which Jacinda Ardern denies.
The Prime Minister stripped Labour MP Iain Lees-Galloway of his ministerial portfolios last Wednesday after it was revealed he had an affair with a former staffer over a 12-month period.
It came after Collins, on that morning, told Duncan Garner on The AM Show that she had passed on to Ardern a tip-off she had received about a Labour Party minister.
Ardern confirmed later that day that Collins had advised her of an email she received related to Lees-Galloway, and Collins conveyed to her that she had asked the individual to relay anything directly to the Prime Minister's office.
Ardern insisted at the time that she had never heard rumours about Lees-Galloway's affair and that she only found out after Collins tipped her off about the email she'd received.
But Collins isn't convinced and thinks Ardern knew what was going on.
"I just alerted her. I didn't know anything about the detail," Collins told Magic Talk. "When she asked me who it was about, I said Iain Lees-Galloway and she said 'Oh, yes right', and that was it. I didn't know anything about it. I think she probably did."
The Prime Minister's office, in response to a request from Newshub on Monday, referred back to Ardern confirming last week that she had not been aware of the rumours and allegations relating to Lees-Galloway.
"At any point where I have things that concern me, I deal with them in an appropriate way, but I don't want to be drawn into hypotheticals or rumours without substance," Ardern said last week.
Collins said she wouldn't have sacked Lees-Galloway if it were up to her.
"I wouldn't have sacked him for an affair... That's between him and his spouse, not me."
Ardern said she sacked Lees-Galloway because he was the Minister for Workplace Relations and Safety and she expected higher standards from him in that role.
Ardern confirmed last week that a ministerial investigation is underway to determine whether Lees-Galloway used taxpayer money to fund his affair.
Earlier last week, Newshub revealed Ardern's office passed on information to Collins about ex-National MP Andrew Falloon over allegations he had been sending inappropriate images to young women.
Collins thanked the Prime Minister last week for how she handled it. But Ardern hit out at Collins for commenting on the tip-off she'd received about Lees-Galloway when speaking to Garner on The AM Show.
"I received information; I passed it onto the leader of the Opposition. The leader of the Opposition has received information and obviously has chosen to deal with that differently," Ardern said at the time.
"That is her judgement. I made mine - she's made hers."
Collins told Magic Talk she revealed the information to Garner because, in his questioning about Falloon, he asked her if she had received anything about Labour ministers or MPs, and Collins didn't want to lie.
"When I was asked by Duncan Garner if there was anyone else, I said yes there is one and I passed it onto the Prime Minister. I didn't say his name."
Collins last week accused Ardern of holding back details about Lees-Galloway.
"She's no doubt got something significantly more than what I know about it; otherwise it wouldn't be an abuse of power in and of itself."
But Collins told Newshub she had no proof to back that up.