Prime Minister Jacinda Ardern says the entrenchment clause in the government's Three Waters legislation was a mistake which the government is fixing.

The government has made a U-turn on the entrenchment rule which would have required 60 percent of votes in the House to overturn the legislation.

Last week, Ardern described the amendment to the bill as "quirky".

Yesterday, leader of the House Chris Hipkins announced it would remove the clause saying it's "not typical", and is not something the government is comfortable with doing.

Ardern told Morning Report the entrenchment provision is very narrow and only applies to the act of selling water assets.

The principle is supported by both the Green Party, which put the provision forward, and by Labour, she says.

The issue is the level of entrenchment put forward, she says.

"Entrenchment is commonly understood to be a super majority or 75 per cent, here we had a novel approach which came before the House at 60, so you had a principle at issue here.".

Asked whether she is aware the entrenchment clause would go to the House at 60 per cent, Ardern says caucus discussions are not shared but entrenchment is commonly understood to be 75 per cent.

"The important thing is it was a mistake, we're fixing it."

Even though Labour supported ensuring that water assets are not privatised, the way this had been done by using the entrenchment clause has wider ramifications, she says.

Ardern refused to point the finger at Local Government Minister Nanaia Mahuta over the issue, repeating that the entrenchment clause was a mistake.

"We are taking this as a team," she says.

"There's actually in my view not a role for any one individual in this issue, this was a mistake, we as a team are fixing it, which will take probably about an hour of our time in Parliament."

Ardern says she has confidence in Mahuta's handling of Three Waters. It has been a hard issue but the government can't ignore what it has been told about the poor state of the country's water infrastructure, she says.

Ardern says the entrenchment clause points to a wider issue that Parliament needs to address.

"The fact that you can put in an entrenchment provision with a lower threshold of this nature and there aren't limitations on where it can apply, this has been a relatively untested area."

A range of politicians now believed some "guard rails" needed to be put around entrenchment provisions, Ardern says.

This needs to come before all parties via the Standing Orders Committee to make sure there are checks to prevent such things happening in the future, she says.

Meanwhile, National Party leader Christopher Luxon agrees the clause should be removed, but says the prime minister needs to front on how it was allowed to happen in the first place.

Greens to keep pushing to protect public ownership of water

The Green Party is disappointed the government is now rejecting the decision to entrench an anti-privatisation clause.

Its local government spokesperson, Eugenie Sage, says the party called on National and Labour a year ago to back its plans to strengthen protections against privatisation of water.

"We flagged in our report from the select committee that we supported 60 per cent entrenchment and we didn't agree with officials' advice."

The Greens put forward the amendment to be voted on, she says.

"We were using the parliamentary process and standing orders specifically provides that if you have an entrenchment provision, it's got to be voted on by the same majority that is in that clause - so we followed the whole parliamentary process, we flagged it in the select committee report."

Sage says the bill is complex and Parliament is in urgency, which they oppose given it provides less opportunity to debate in the committee stages.

-RNZ.