Political drama peaked yesterday as National MP Jami-Lee Ross was identified as the leaker of a report into Simon Bridges' travel expenses.
Mr Ross sent out a flurry of tweets just minutes before National Party leader Simon Bridges made the announcement, and now today's caucus will decide Mr Ross' fate.
1 NEWS political editor Jessica Mutch McKay spoke to TVNZ's Breakfast this morning about the National Party's political turmoil and what can be expected at caucus.
"It was extraordinary yesterday. When those series of tweets came out just six minutes before Simon Bridges was set to make the announcement, I think there was an audible gasp in the press gallery here," Mutch McKay said.
"Just, what he was revealing and what he was alleging just added a whole new layer into this mix."
Mutch McKay says today is "crunch time" as caucus meets later this morning.
"That's when his caucus colleagues will decide his fate, and there are lots of options for how this could play out. Jami-Lee Ross could dig in his heels, he could put up a fight and he could decide to stay on as an independent MP.
"It's almost certain that he is going to be suspended from caucus this morning and then expelled from the party over time."
Mutch McKay said if Mr Ross "decides to go quietly", he may choose to resign from parliament, prompting a by-election.
"Because Simon Bridges is so against this, he's not going to do that for Jami-Lee Ross in this instance, even though, perhaps, he would like to, so a lot of very interesting things at play here."
However, she says Mr Ross' political career is unlikely to survive in the National Party.
"By sending out those tweets, that basically seals his fate. His National colleagues will no doubt come out and suspend him today.
"Simon Bridges yesterday, in a press conference, said, 'Look, suspension is likely,' bearing in mind that it is a caucus decision. But he didn't come out really strongly saying, 'That’s definitely what I'm going to do', so it will be up to caucus to decide, but that's definitely the hint that we're getting from Simon Bridges and behind the scenes as well."
Mutch McKay said the incident came about after a recent falling out between Mr Ross and Mr Bridges.
"I don't think there was any secret about that - in fact, Jami-Lee Ross mentioned that in his tweet. And when he was the party whip – now, the party whip is the person who’s in charge of managing the MPs, if you like – they have a lot of information, they're in this circle, all of that and Jami-Lee Ross has decided to come out and use some of that.
"Now, there's Jami-Lee Ross saying one thing, Simon Bridges saying the other - both denying the allegations that either one has made - so it's an absolutely messy situation for the [National] Party, and not one that they want to be in. And on top of that, the issues of leadership for Simon Bridges, and it’s going to be a very busy and stressful day, you’d imagine, for the National leader."
She says the party’s political fracas "raises questions about the internal party dynamics" and Mr Bridges' leadership in the National Party.
"Now, Simon Bridges is very adamant that he has the full support of the party – this is one person acting alone, and that's certainly been the message that a lot of those senior MPs have been saying publicly as well, but it raises the question and it also brings questions about whether his leadership is so secure. He needs to take a stand today – it's a big day for his leadership today, and he will be tested and judged on that, and we'll see the outcome of that in the next few days."