Hamilton West MP Gaurav Sharma has been expelled from the Labour Party caucus.
The matter is also being escalated to the wider Labour Party to consider further disciplinary action.
Sharma told reporters he had been expelled as he exited the caucus meeting this morning.
"It's not easy, obviously, walking into a situation like this," he said. "I'm gonna go and have a coffee, and take some time to think about it, genuinely."
He said the meeting was respectful: he got the chance to speak, and other members got a chance to speak too before the vote by secret ballot.
"Finally there was a vote and so the caucus has decided - I think there was one abstention and one no - to expel me from caucus.
"I did say if I've broken people's trust I apologise for that."
The Labour whips office said Sharma was present and could vote on his expulsion - one of 62 votes - and confirmed the voting record of one abstention and one vote against.
A second vote followed which Sharma was not present for, on whether to refer the matter to the Labour Party. The result was unanimously in favour.
He said when they were in the room no one had really wanted to talk about how they had arrived at that point.
"When I tried to actually raise the examples, when I tried to talk about the concerns - the specifics - I was told that I can't talk about it, and the only thing they really wanted to talk about was the expulsion and the suspension.
"The fact, again, that I have raised some serious concerns regarding bullying, the fact that, you know, I have said there needs to be an independent investigation first of all into the person who's bullied me but also an independent investigation against me if anybody has raised any serious concerns about bullying from my side."
He would keep pushing for an independent investigation regardless.
"I was the one who raised concerns regarding my staff, not the other way around, and that's when the bullying from the whips started.
"I think asking for an independent and fair trial is something that, you know, all New Zealanders should have the right to ask for, whether you work in Parliament or you work anywhere else."
"Genuinely when I brought that article on Thursday I thought on Friday the prime minister would come out and say 'let's do an independent investigation, a fair trial, and everybody just, you know, get back to work'. So when that didn't happen and the prime minister said there wasn't any bullying, I had to then release the screenshots."
He said he had not made a decision on whether he would remain as an independent MP.
"The fact, again, that I have raised some serious concerns regarding bullying, the fact that, you know, I have said there needs to be an independent investigation first of all into the person who's bullied me but also an independent investigation against me if anybody has raised any serious concerns about bullying from my side."
He denied suggestions he was taking advice from anyone inside the party or other parties.
"I would just say, lots of people have reached out to me from all across but I haven't been taking advice from anybody specifically and none of it has been planned in a some sort of way, it's basically what's happening every day and I just try to respond to that."
The news was confirmed in a statement from Prime Minister and Labour leader Jacinda Ardern.
"The Labour Caucus has voted to expel Dr Gaurav Sharma from caucus, effectively immediately," she said. "The Caucus also voted to refer the matter to the New Zealand Council of the Labour Party for them to consider any further disciplinary action."
She said the decision meant Sharma would no longer receive support from the party, or have access to the caucus in any way. He would have the right to attend select committees, but would not be a member of one.
"When Gaurav went public about his staffing issues 12 days ago our response was one of concern. We attempted to offer support and find a way to resolve his concerns. We offered mediation and a pathway back for him.
"Despite providing an opportunity to resolve his issues and to rebuild trust he has repeatedly demonstrated that he no longer wishes to be a member of the caucus. His consistent and ongoing breach of the caucus rules has resulted in the complete loss of trust by his fellow Labour MPs."
She said Labour's whips and the Parliamentary Service had sought to resolve staffing issues within Sharma's officer for more than a year, but rather than accept the issues raised or the need to take steps to address them he had "consistently contested the process".
"As a Labour team we remain committed to ensuring that Parliament is a positive place for our staff. We have however highlighted to the Speaker areas where we believe that the new procedures under the Francis Review could be improved, and asked that he consider whether these recent events could be a case study to help improve these processes.
"There are definitely things to be learned from this episode, but none of it justifies the recent behaviour of Gaurav."
She said the decision concluded the matter from the Labour caucus' perspective.
"Our focus remains on the significant issues New Zealanders are grappling with and our responsibility to serve them - not the interests of an individual MP."
Sharma was suspended from the caucus last week for repeated breaches of trust.
Prior to the meeting, Sharma said he was not nervous but had not thought as far as what would happen if he was expelled.
"No I don't feel nervous, you know. I feel sad and sorry that we are elected members of Parliament and our own voice is being silenced and if people can't stand up for themselves, what job are they doing standing up for their constituents.
"Similarly for the leadership of the party, it's all talk. All the values they talk about at conferences, at Ivy league universities, at 1pm Covid briefings, but if you're not prepared to put your money where your mouth is then what's the point of talking about this."
He said what was needed was an independent investigation.
"What we need is justice, an independent investigation, it's not something crazy to ask for, you know."
"These MPs are still getting in touch with me and saying they're the ones who have been bullied, so maybe they don't trust the party and the leadership as well otherwise why would they be contacting me still and talking to me about it."