If tomorrow is the day of reckoning for National MP Jami-Lee Ross, it is doubly so for National's leader Simon Bridges.
In setting out his case against Jami-Lee Ross as the likely source of the leak of Bridges' travel expenses, Bridges said he was confident he still had thesupport of the rest of caucus.
Tomorrow that will be put to the test.
The National Party caucus will be asked to suspend Ross from the caucus, or even expel him.
If it does not happen, it will amount to a vote of no confidence in Bridges and he will from that moment be a dead man walking.
Those MPs who have spoken have made it clear they will back Bridges.
Maggie Barry said it was "extremely disappointing to see disloyalty on this scale."
That is the key word: disloyalty.
It is no small thing to suspend an MP.
National Party leader Simon Bridges sets out findings on Jami-Lee Ross with deputy leader Paula Bennett alongside him. Photo / Doug Sherring
Since 1999 two MPs have been suspended from National, both while in Opposition and both for disloyalty to a leader.
There was Maurice Williamson in 2003 for openly criticising Bill English's leadership and Brian Connell in 2006 for questioning Don Brash's private life.
In Labour, Chris Carter was suspended in 2010 after he was caught out as the source of an anonymous letter to Press Gallery offices questioning Phil Goff's leadership.
National MPs are accustomed to more than a decade of stringent discipline and will find themselves in a foreign land when they go into that caucus meeting.
They will have the full gamut of information laid before them as well as the investigation which finds it likely - but not definite - that Ross leaked Bridges' travel expenses.
Bridges has pointed to "other matters concerning his conduct" that suggest a pattern.
The information awaiting them is understood to include further instances of disloyalty as well as personal behaviour.
So it is now immaterial whether Ross did leak Bridges' expenses or not. Any undermining of the leader is intolerable, especially if it leaks out into the public which it inevitably does.
Ross himself has effectively admitted to disloyalty in the string of pre-emptive strike tweets he sent out in advance of Bridges' announcement, saying he had fallen out with Bridges, questioning some of his decisions and his personal poll ratings.
He also pointed to what he claimed was "illegal" behaviour by Bridges relating to election donations, saying after he confronted Bridges with it he was forced to go on medical leave. Bridges has denied anything illegal was asked.
Those tweets and the implicit threats within them will help Bridges' case tomorrow.
Whether Ross' wider behaviour would have come to light had it not been for Bridges' leaker-hunt is now moot. He would have to go anyway.
Bridges has faced trenchant criticism for his decision to hold the investigation into who leaked his expense details a few days ahead of their public release.
That seems to be based on the theory you should not lift a stone if you fear the snake lying under it.
In reality, Bridges had no choice. Had he not rooted out a culprit it would have dogged him until the end of his leadership and ultimately hastened it.
As Shane Jones put it when David Cunliffe was disciplined by then Labour leader David Shearer "when you build a whare, if you see a huhu grub you've got to toast it or roast it because your whare will go pirau [rotten] and fall down."
Admittedly, Shearer's whare fell down soon after despite the toasting he administered. Disloyalty can be contagious and Shearer was also a casualty of what was deemed low party polling.
Bridges will be desperately hoping that particular huhu does not hit his whare too.
