Labour minister Michael Wood's actions broke the Prime Minister's trust and are sackable offences, National Party MP Erica Stanford believes.
Chris Hipkins on Tuesday said he'd stood down Wood as the Transport Minister. The Prime Minister had not yet made further decisions about whether he will return to the role, with Pecuniary and Other Specified Interests registrar Sir Maarten Wevers now probing the matter.
The standing down came after revelations Wood had earlier failed to declare his shares in Auckland Airport. It was then revealed he was asked 12 times by the Cabinet office about selling the shares - but didn't.
On Thursday, the under-fire minister said he'd finally sold the shares.
Hipkins has characterised Wood as "a hardworking, diligent, conscientious person" and said he couldn't "quite understand what has happened here".
The Prime Minister said he "clearly" would've liked to have known about the shares situation earlier.
"Having said that, the responsibility rests with Michael Wood."
Speaking to AM, Stanford - who usually has Wood alongside her for the show's weekly political panel - didn't believe the book had closed on the saga just yet.
"When you look at what's happened over the last few years - there have been a number of very serious things that have happened. He didn't register it on his pecuniary interests, he didn't sell his shares, he was told 12 times to do it - still didn't do it," Stanford said.
"He misled the Cabinet office and he misled the Prime Minister and, I'm not calling for him to be sacked, what I am saying is - he will be. You cannot mislead the Prime Minister… his position is completely untenable, you just can't do that.
"I don't think Chris Hipkins has got any choice in the matter."
Stanford said Wood's actions were "very, very serious".
However, Labour minister Ginny Andersen - appearing on AM in Wood's place - said it was important to note, "Michael has been upfront… and that he has sold those shares".
"He's made it clear that it's deeply regrettable that wasn't done earlier and we're ready to move on.
"I'm not going to get in and understand why they weren't sold earlier."
Wood said the shares situation had been "difficult", "but I take responsibility for it".
He said while in the process of selling the shares, which began in February last year, he was meant to receive information from the share register - but didn't because it had an old email address.
"I acknowledge the faults. I should have followed up on that and I didn't," Wood told reporters.
"This is something I lost sight of.
"I have a very large job… Some of these things in my life administration, I have let slip. I shouldn't have."
Wood denied his shareholding impacted any decisions he made as a minister.