Jenna Lynch: Christopher Luxon too trigger-happy with call to sack Nanaia Mahuta, but her clock is ticking

ANALYSIS: Christopher Luxon has pulled the 'sackable offence' trigger.

It's something an Opposition leader should reach for rarely, so as not to be seen as the boy who cried "sack her". 

But Luxon on Wednesday hollered it out in the house.

"When will the Prime Minister sack her?" he asked.

Nanaia Mahuta was his target - he sniffed blood around the entrenchment debacle.

The Government was this week forced to take its controversial Three Waters reforms back to the House to remove a provision that entrenched public ownership of water assets. 

Constitutional experts rightly cried foul. Entrenchment usually requires 75 percent of MPs to agree and is usually only used for matters of electoral importance like the voting age. 

In this case, 75 percent was not achievable so the Green Party put up an amendment with a novel mega majority of 60 percent, meaning it would take 60 percent to repeal. 

Labour voted for the amendment but has since admitted it made a mistake but won't say how that mistake was made. 

It's been implied that caucus wasn't fully aware of the 60 percent anomaly - though no one has outright said so, hiding behind the confidentiality of caucus conversations.

Newshub's been told Nanaia Mahuta did not tell her caucus colleagues about the 60 percent fact and it seems many of them were unaware of it. 

It's looking increasingly like Labour thought this amendment wouldn't pass - it looks like it tried to pull a political stunt to make it look like National was going to privatise water assets because the party wouldn't vote for entrenchment. 

Luxon has guaranteed they will not privatise water assets a number of times. 

On Wednesday, the National Party dug out Cabinet's call on Three Waters entrenchment. Black and white, Cabinet "agreed that the Bill should not entrench the privatisation provisions in the Bill".

Luxon went for it in the House and next came the screaming press release: "Prime Minister should sack Nanaia Mahuta".

It claimed Mahuta had defied her colleagues, therefore breaching the cabinet manual, 

"The Cabinet Manual is clear. It says, 'Once Cabinet makes a decision, Ministers must support it, regardless of their personal views'."

That position fails to take into account that the whole caucus - which includes the whole Cabinet - made the decision to support entrenchment. 

But Mahuta’s clock is ticking. The runway in her role as Local Government Minister appears to be shortening. It's been untenable for some time for her to hold onto both the Foreign Affairs and Local Government roles.

The Prime Minister will likely allow Mahuta to finish getting the Three Waters reforms through the House but then she will feel her job is done. 

There is a reshuffle early next year. Associate Local Government Minister Kieran McAnulty is well-primed to take over the role. 

Having said that, it could be concluded Luxon has drawn a reasonably long bow and has been too trigger-happy with his call for Mahuta's head. 

The Cabinet paper is enough of a point to score a tiny hit in the house but it's no smoking sacking gun. 

Jenna Lynch is Newshub's Political Editor.