Chris Hipkins has tough decision to make as Michael Wood's reputation 'very tarnished' - former United Future leader Peter Dunne

The reputation of Michael Wood is now "very tarnished", according to one of New Zealand's longest-serving MPs.

Wood, the now-suspended Transport Minister, was asked 12 times by the Cabinet Office to sell his shares in Auckland Airport, Prime Minister Chris Hipkins revealed in Parliament on Wednesday. However, those requests fell on deaf ears.

Wood said the selling off of those shares is now underway.

Former United Future leader and ex-Labour MP Peter Dunne told AM Early Hipkins had a tough decision to make.

"It looks either like incredible stupidity or incredible defiance on his part," Dunne said of Wood.

"You've got to ask, 'What's the damage in keeping him on?' He's looking very tarnished now and it seems to me that Chris Hipkins has got a pretty difficult decision to make in the next couple of days as to whether he retains him or whether he cuts the cord completely."

With Wood being an experienced MP and senior minister, Dunne believed Hipkins had a difficult balance to strike.

"If he fires Wood, he gets some kudos for being decisive but then that's another blow - and another minister promoted and the image of a Government in shambles," Dunne told AM Early host Michael O'Keefe.

Dunne believed there was the risk of more revelations should Hipkins choose to retain Wood.

"It's a difficult balancing act and I guess the best thing for Wood would be to make a clean breast of things and, if there are other skeletons in the cupboard to be revealed, get them out of the way as quickly as possible. Otherwise, this could drag on for a little while and be quite debilitating."

With Wood's case being one of a string of ministerial misdemeanours in recent months, Dunne believed the controversies would be "frustrating Hipkins incredibly".

"He can't be seen now to be leading a Government doing things. Rather, he's running around putting out fires in his own house and I think that's incredibly difficult for him and incredibly frustrating."

Dunne said other Labour MPs would also be frustrated.

"They'll be starting to get feedback from constituents - they'll be starting to have their morale dashed a little bit.

"I don't think people are too focused on the particular details of the issue but it's the overall image it's created that looks like a Government in chaos at the moment."

Dunne believed Hipkins had a tough job steering Labour back in the right direction.

"How do you resurrect this show and get it back on track?"

Watch the full video for more.