The New Zealand Herald understands MPs met at 8pm, but Sharma says he was not told of the meeting.
He found out about it after a message - including a photo of Kelvin Davis on the zoom call - was sent to him by mistake.
"Apparently caucus had a full meeting at 8pm yesterday with all members except me and the decision was predetermined," Sharma said in a text message sent to NZME.
It comes as Labour's caucus is meeting this afternoon, as announced by Prime Minister Jacinda Ardern yesterday in her post-Cabinet press conference.
Ardern did not mention any plans for a meeting set for last night.
Sharma today told the Herald he was unsure whether he would make today's afternoon meeting, given he had other engagements.
However, he expressed his desire to have a "fair trial".
Ardern is expected to front media about 4pm.
The Hamilton West MP, who went public with allegations of "rampant" bullying within Parliament last week in a Herald column, has also claimed some MPs - including some in the Labour Party - have sent him supporting messages and are grateful he has spoken out.
Sharma told the Herald that if he was expelled from the party, he might stay on as an independent MP.
"I'll try my best to make it [the meeting] but as I said, I'm just trying to squeeze everything in."
Sharma said he had been given "very short notice" of the meeting, claiming he was told by current senior whip Duncan Webb between 5-6pm yesterday that the meeting would be held today.
He understood there was only "one point on the agenda" - Sharma's allegations and how they were discussed publicly.
