Opposition parties are accusing the Prime Minister of not taking tax avoidance seriously.

It comes as the Government has ordered a review of the country's foreign trust disclosure rules in light of the Panama Papers leaks, which continue to embarrass the rich, the famous, and politicians overseas.

The Soap Box: Key's latest position on Panama Papers

But New Zealand First leader Winston Peters said his party is not settling for the Government's response.

"When this country's reputation has been so traduced on the issue of being a tax haven, the Prime Minister has got to take this issue seriously and he clearly has not."

Mr Peters is critical of the Government's decision to choose international tax expert John Shewan to lead the review.

SEE ALSO: Govt appoints international expert to investigate NZ tax laws

He said a proper inquiry with full powers to obtain disclosure is needed and by a body not contaminated with New Zealand establishment associations.

Labour leader Andrew Little said a review has to involve more than one tax advisor behind closed doors if it is to have any credibility or salvage the country's international reputation.

Mr Little said John Key is doing the absolute minimum to appear as if he is addressing the issue.

"Terms of reference looks like it's designed to lead to a report that tells us that everything we're doing is legal and no change is required.

"There's no examination of whether what we're doing is right, and no challenge to it. It just looks like a terms of reference set up to give an answer that the Prime Minister wants."

Meanwhile, Mr Little is offering assurances he has no connections to foreign trusts.

WATCH: Key grilled on Panama Papers

John Key has been questioned by media on the matter and he said he is totally 100 percent confident his tax affairs are both above board and totally clean.

"I've never used a foreign trust, no, I've never used a foreign trust. I've only had two trusts."

One, he said, is the JP and BI Key family trust which is on his pecuniary interest declaration, and the Aldgate blind trust.

Labour Leader Andrew Little is also disavowing having any foreign trust dealings.

"I don't have a foreign trust, I'm not a beneficiary of any foreign trust, I don't have a trust full stop. It's not the sort of approach I take to my affairs."

Mike's Minute: Taxing Times