COVID-19: Todd Muller couldn't challenge Government on isolation escapee because of National MP's privacy breach - political scientist

A political scientist says the Opposition has "gone quiet" over Auckland's managed isolation absconder due to one of its MPs leaking details about New Zealand's COVID-19 patients.

While Health Minister Chris Hipkins was revealing a man had left a managed isolation facility, attended a supermarket, and later tested positive for COVID-19, National leader Todd Muller was dealing with his own debacle. One of his MPs, Hamish Walker, quit on Wednesday after outing himself as the person who passed on leaked confidential COVID-19 patient information to three media outlets last week.

Dr Edwards, of Victoria University, said the Opposition's sketchy credibility as a result of the leaking saga has meant National couldn't challenge the Government over the managed isolation bungle.

"That's the role of the Opposition - over the last 24 hours, they've gone quiet on what has been a bungle at the border," Dr Edwards told The AM Show on Thursday.

"They [National] haven't been in the media and it's the role [of the Opposition], and we're let down in the adversarial political system when the Opposition isn't on the case."

Voters may be questioning The National Party, Dr Edwards said, with issues around dirty politics now being raised. Muller, however, insists there's no history of dirty politics within National and accused Walker of going behind his back.

Dr Edwards noted it's not the first scandal to strike the party in recent years.

"It comes after Jami-Lee Ross, it comes after all these other rogue MPs [who] haven't had proper discipline within the Caucus," Dr Edwards said.

"National have let down the country in what they've done - people won't just have lost faith in Hamish Walker.

"How many others are there going to be like this?"

Muller said on Wednesday Walker made an error of judgement that cost him his career, despite working hard for his Clutha-Southland electorate over the past three years.

Labour, however, isn't exempt from scrutiny and also in damage control over the isolation escapee. Dr Edwards said both of New Zealand's major political parties had let the country down.

"I'm not sure which is worse but they're both denting the public's confidence," he said.