Prime Minister Jacinda Ardern says the entrenchment clause in the government's Three Waters legislation was a mistake - but is refusing to explain how it came about or who is to blame.
The government has made a U-turn on the entrenchment rule which would have required 60 percent of votes in the House to overturn provisions protecting against privatisation.
Last week, Ardern described the amendment to the bill as "quirky".
Yesterday, leader of the House Chris Hipkins announced the clause would be removed saying it was "not typical", and was not something the government was comfortable with doing.
Ardern told Morning Report the entrenchment provision was very narrow and only applied to the act of selling water assets.
The principle was supported by both the Green Party, which put the provision forward, and by Labour, she said.
The issue was the level of entrenchment put forward, she said.
"Entrenchment is commonly understood to be a super majority or 75 percent, here we had a novel approach which came before the House at 60, so you had a principle at issue here," she said.
Asked whether she was aware the entrenchment clause would go to the House at 60 percent, Ardern said caucus discussions were not shared publicly but entrenchment was commonly understood to be 75 percent.
"The important thing is it was a mistake, we're fixing it."
Even though Labour wanted to prevent water assets being privatised, using entrenchment had wider ramifications, she said.
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 said.
"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 said she had confidence in Mahuta's handling of Three Waters. It had been a hard issue but the government could not ignore what it had been told about the poor state of the country's water infrastructure, she said.
Ardern said the entrenchment clause pointed to a wider issue that Parliament needed 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 said.
This needed to come before all parties via the Standing Orders Committee to make sure there were checks to prevent such things happening in the future, she said.
'Stain on the prime minister's credibility' - Luxon
National Party leader Christopher Luxon agreed the clause should be removed, but said the prime minister needed to front on how it was allowed to happen in the first place.
He repeated his position this afternoon.
"It's a bit of a stain on the prime minister's credibility, quite frankly, about what she did or didn't know," he said. "How she's explained it has been really poor, there's no clarity about what she did or didn't know and her involvement in it.
"It speaks to poor chairmanship, poor governance, poor implementation of caucus and/or Cabinet meetings.
"You should know [if] there's an entrenchment provision going into a critical piece of legislation that's deeply unpopular with the New Zealand people."
Asked if Ardern was being sneaky or asleep at the wheel, he said "It's a loss of attention to detail, right, and actually what New Zealanders are crying out for at the moment is a government that will actually get things done and deliver outcomes."
He said the matter was a "real mess", as had been the whole three waters project.
"Frankly the government should stop and abandon the plans and actually get around the table with councils and build an enduring solution."
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, said 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 percent entrenchment and we didn't agree with officials' advice."
The Greens put forward the amendment to be voted on, she said.
"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 said the bill was complex and Parliament was in urgency, which they opposed given it provided less opportunity to debate in the committee stages.