Tensions in Parliament boiled over this afternoon, with the opposition leader booted out of question time for criticising the conduct of the speaker.
That prompted most of the National caucus to follow, albeit slowly.
National leader Simon Bridges was kicked out of the debating chamber, following a series of questions to the prime minister on convicted drug smuggler Karel Sroubek.
He said "here comes the protection," implying Speaker Trevor Mallard was jumping to Jacinda Ardern's defence.
Speaking to reporters afterwards, Mr Bridges was defiant.
"I was asking the prime minister serious questions about the Sroubek fiasco, she wouldn't answer and the speaker leapt to protect her. I called him on it."
It was put to him Mr Mallard would view that as a serious challenge to his authority as speaker.
"You can talk to him about what he thinks", replied Mr Bridges.
"We're talking about very serious matters there should be answers to and she knows about ... and Mr Mallard who, look, every question time gets to his feet, with what I think are fairly trivial matters really, to break the flow and protect."
National MPs trickled out of the house over the half an hour following Mr Bridges' ejection; Shadow Leader of the House Gerry Brownlee was also ordered to leave.
About 10min post the ‘mass walk out’, the opposition. Have almost ‘walked out’... post being whipped (which didn’t really work), and then Aunty Paula giving them the hard word.— Kiri Allan (@KiriAllan) December 5, 2018
The leadership battle lines being drawn?
Deputy Prime Minister Winston said today's slow walk out was hardly the most inspiring show of support for a party leader.
"What was most damaging was the way they left after him; they went out in dribs and drabs.
"It looked like the first loyal group when about six walked out, then about 12 others decided they might be loyal and then the rest decided they should show some loyalty as well - it was seriously disorganised."
Ms Ardern rejected any accusations she was not fronting questions on the matter, and Mr Mallard declined to comment on the criticisms levelled against him by Mr Bridges.