Labour's national council will deal with Chris Carter's attempt to undermine leader Phil Goff on Monday, party president Andrew Little confirmed.
The MP was expelled from the Labour caucus after sending an anonymous letter to the media on July 29 which said a coup was planned against Mr Goff because he couldn't win the next election.
Mr Carter was quickly uncovered as its author and now has to face the party's national council, which is expected to suspend or expel him.
Mr Little told NZPA Mr Carter's lawyers had agreed to October 11 for a hearing, when Mr Carter will get the chance to defend himself.
He wasn't sure whether the council would reach a decision on that day but said he wanted to get it over with as quickly as possible.
The party needs to finalise the situation because its annual conference is being held in the middle of this month, and there has been speculation Mr Carter might turn up.
That would be a big distraction from the positive publicity Labour expects from the conference, and Mr Goff said today he wouldn't be welcome.
"I'd be very surprised to see him there," Mr Goff said.
"He is the Member of Parliament for Te Atatu and he is an independent."
Although Parliament has ruled that Mr Carter is no longer a Labour MP he insists he has the right to be one, and at present is Labour's only nomination for the Te Atatu seat in next year's election.
Mr Little said yesterday two people had confirmed they would lodge their nominations before the deadline of 5pm on Friday and challenge Mr Carter.
He said later he didn't know whether any nominations had been formally submitted "but the level of interest is intensifying and I'm even more confident now there will be more than one nomination by the end of Friday."
Mr Little isn't concerned about nominations closing before the council holds its meeting to decide Mr Carter's future.
He said if Mr Carter was suspended or expelled, and there had been no other nominations lodged, the party could re-open the process.