Meka Whaitiri has announced she has resigned from Labour and intends to sit with Te Pāti Māori in Parliament and stand for the party at the election.
She said crossing the floor was not an easy decision, but the right one.
It appears many of her Labour colleagues were caught off guard, with the Prime Minister saying he hadn't spoken with Whaitiri.
After her announcement on Wednesday, Prime Minister Chris Hipkins made the decision to sack Whaitiri as a minister.
The Speaker has declared that Whaitiri is now an independent MP for parliamentary purposes.
Newshub's live updates have finished.
6:10pm - Here's Newshub Political Editor Jenna Lynch's report on the day's events. You can watch and read it here.
3:45pm - Labour's Kiri Allan met with Whaitiri on Wednesday morning for a "fulsome conversation". She's just told media Whaitiri has made her decision and its "a new dawn".
Allan said Whatiri was "calm" in her decision-making.
"She's made that decision. She's been through that process and that's what she was clear about with me. That was that. There is no changing her mind."
Asked if Labour is paternalistic towards Māori MPs, Allan rejected that.
"Every single day, we all have a decision about where we strap on our boots and what we do with our time. She, for 10 years, made that decision to do that under the umbrella of Labour. She has made a new decision today."
Allan said she is "unapologetically Māori".
"I am unapologetically Kiritapu and I am unapologetically from the East Coast."
Allan said Labour has held the Ikaroa-Rāwhiti seat for a long time and it would put up a good fight at the election against Whaitiri and Te Pāti Māori.
The MP said Whaitiri asked if she wanted to come to Te Pāti Māori as well. But Allan said no. She said it was more of a "giggle than anything else".
3:20pm - Nanaia Mahuta said Whaitiri has made her own decisions, but she feels Labour has achieved a lot for Māori.
"When I think about the range of reforms that improve the wellbeing of Māori but also create more opportunites for Māori to have a say in what impacts most in their lives, I think most Māori will see how much progress has been made in the last six years."
3:10pm - Willie Jackson was clearly sad about the situation when he spoke to reporters.
"She never rung me or contacted me. That was disappointing. I was very disappointed actually. We have got a close relationship. She was my partner in terms of chairing the Māori caucus."
He said Whaitiri has never raised issues with him.
"She was always a strong advocate for Māori. She has done a terrific job through the cyclone."
He wishes her all the best.
"She was a leader and I was proud to work with her. It would be nice to hear from here.
Jackson said it was assumed she would run again for Labour.
2:30pm - National's Christopher Luxon asks the acting Prime Minister if the Prime Minister has lost control after the Whaitiri situation.
Carmel Sepuloni calls it a "party matter" and Whaitiri is no longer a minister. But she says the Prime Minister remains in control. The Government continues to look forward to serving New Zealanders, she says
She says she is proud of the committments made to regions affected by the cyclone. Kieran McAnulty is now serving as the ministerial lead for the cyclone recovery for the Hawke's Bay.
ACT's David Seymour asks if the Prime Minister had considered taking a roll at the start of meetings, to make sure no other ministers have been lost. The question is ruled out of order.
2:10pm - The Speaker confirms he has received no letter of resignation from Whaitiri, signed or unsigned. But he has received an indication via email from Whaitiri saying she has withdrawn her vote from the Labour Party for parliamentary purposes. He believes he has "followed the law to the letter".
2pm - The Speaker says Meka Whaitiri is now regarded as an independent member.
National's Michael Woodhouse notes that Whaitiri said on Wednesday morning she had told the Speaker she was resigning. He believes, on the face of that, that would trigger the so-called waka-jumping legislation. He asks the Speaker to table correspondence from Whaitiri.
The Speaker replies that any MP can say whatever they like outside of the House, but when it comes to the waka-jumping legislation, there are specific events that need to happen before he declares a seat vacant. He says those events have not happened.
The full debate can be watched in the livestream above.
1:30pm - We will shortly be livestreaming Parliament TV. The events in the House should provide some clarity around whether Whaitiri has vacated her seat by writing to the Speaker with her resignation from Labour.
If she did and the necessary requirements were fulfilled, then she vacates her seat. If some conditions weren't met or she withdrew her letter, she could remain in the House as an independent and vote along Te Pāti Māori's lines.
All eyes will be on the Speaker at 2pm.
12pm - Sepuloni said Labour is confident there aren't any other MPs considering standing down or moving on outside of those already announced.
"We are confident that there aren't," she said.
11:50am - Davis won't speculate on Whaitiri's motives.
It was her decision and she did things the way she wanted to do it. He believes the party showed Whaitiri that it valued her.
Davis says the wheels aren't falling off the bus. He says it is the decision of an individual and the Labour Party remains committed to representing New Zealand.
Sepuloni said, "these things happen across political parties sometimes in different ways".
Davis said Labour and Te Pāti Māori engage respectfully.
11:45am - Deputy Labour leader Kelvin Davis doesn't believe this is damaging for the party. The Labour Party caucus is just keen to get on dealing with cost of living and cyclone recovery issues, he said.
Up until Tuesday, it was Labour's understanding Whaitiri would be standing for Labour. It's taken the party by surprise, he said.
Sepuloni said this situation won't distract the Government from the issues on the east coast of the North Island following the cyclone.
The acting Prime Minister said Prime Minister Hipkins was disappointed and surprised by the news.
Davis reiterates it is disappointing and something the party would have preferred not to happen.
11:40am - Speaking to media, Sepuloni said the Government doesn't feel the need to invoke the waka-jumping legislation. She said the other way for Whaitiri to be waka-jumped is through writing to the Speaker. But that's now up to them.
Sepuloni said it's "diappointing" and "unexpected". It's hard to see a colleague go, she said.
No reason has been given. No contact has been made with the leadership by Whaitiri.
Sepuloni said she heard a rumour around midday from a member of the public and then it developed from there.
She said it's for Whaitiri to explain her reasoning. We've just go to move on, she said.
11:30am - New statement from the Government:
Meka Whaitiri has been removed from her ministerial responsibilities, effective immediately, Acting Prime Minister Carmel Sepuloni has announced.
"Prime Minister Chris Hipkins made the decision on confirmation of Meka Whaitiri's resignation from the Labour Party this morning," Carmel Sepuloni said.
"As Acting Prime Minister, I have advised the Administrator of the Government to give effect to that decision this morning.
"Obviously we're disappointed in Meka Whaitiri's decision. But we are moving on.
"Decisions on the permanent allocation of the portfolios will be made in the next week.
"Until then, Kieran McAnulty will be the Acting Hawkes Bay Lead Minister for Cyclone Recovery, Ayesha Verrall will be the Acting Minister for Food Safety, Peeni Henare will be the Acting Minister for Veterans, and Damien O'Connor will be the Acting Minister of Customs. All Associate Portfolios will return to the lead Portfolio Minister.
"Labour is proud of our track record for Māori. We've established the Māori Health Authority/Te Aka Whai Ora, boosted Whānau Ora funding to historic levels, created the Matariki public holiday, and introduced New Zealand history in schools.
"The cost of living and cyclone recovery are matters that affect all New Zealanders, including Māori.
"They and the people of Hawke's Bay and Tairāwhiti who are recovering and rebuilding from the damage of Cyclone Gabrielle remain our strong focus as we continue to support Kiwis through globally turbulent times," Carmel Sepuloni said.
10:50am - Acting Prime Minister Carmel Sepuloni and deputy Labour leader Kelvin Davis will speak to media just after 11:30am. We will livestream that above.
10:30am - The ACT Party says Whaitiri's defection is a "distraction" from issues Kiwis face.
"How is Hipkins expected to manage 60,000 public servants when he can’t keep track of 65 MPs?" leader David Seymour says.
"Labour is caught up in internal politics when they should be addressing issues like keeping New Zealand’s streets safe, making life affordable, and getting on with the rebuild in Hawke’s Bay and Tairāwhiti.
"The real losers here are the long-suffering residents of cyclone-affected regions. They’ve watched the Government muck around for months and have now seen two Cyclone Recovery Ministers depart."
10:15am - Te Pāti Māori co-leader Debbie Ngarewa-Packer is speaking to the crowd about the purposes of the party and its political activism. She says the movement will welcome back people who haven't been part of the party recently.
10:05am - There are technical issues with the party's Facebook stream, but Tamihere is continuing to discuss why Whaitiri is leaving Labour.
Whaitiri is now speaking. She acknowledges Te Au-Skipworth and her whanau. She is clearly emotional. Te Au-Skipworth had been selected for the seat, but is stepping aside for Whaitiri.
"The point here whanau is Māori political activisim is part of being Māori," she says.
She says the decision to cross the floor isn't an easy one, but it's the right one.
She's notified the Speaker she has resigned from Labour. Effective immediately, she intends to be seated with Te Pāti Māori.
10am - Meka Whaitiri is at the marae alongside Te Pāti Māori co-leaders Debbie Ngarewa-Packer and Rawiri Waititi.
The party's president John Tamihere says it is "Meka's day". He acknowledges current candidate Heather Te Au-Skipworth for stepping aside for Whaitiri. He says Whaitiri wanted the announcement made on the marae.
"It's a magnificent day for Māori."
He says former leader Tairana Turia once walked away from Labour. He says Whaitiri is returning to her whakapapa.
"This takes courage... she is walking away from a ministerial job... she is walking into an unknown but she is doing it for the mana of our people."
9:50am - We are now waiting on the Te Pāti Māori livestream to be published.
9:30am - We are anticipating an announcement from Te Pāti Māori at 10am. We will livestream that above and bring you updates as they come.
From earlier: Labour ministers and MPs appear caught off guard over Whaitiri's suspected resignation from the party.
Prime Minister Chris Hipkins, Whaitiri's boss, said on Wednesday morning he hadn't spoken with her. He's just arrived in London ahead of King Charles' coronation.
"I haven't had a conversation with Meka Whaitiri yet and I obviously want to do her the courtesy of hearing what she has to say if anything before I make a comment on it," he said.
Newshub has been speaking to ministers and MPs at Parliament on Wednesday morning.
Labour's David Parker said he hasn't spoken to Whaitiri and had nothing to add.
But he believed this wasn't a sign of Hipkins losing control of his party.
Stuart Nash, who was recently sacked from Cabinet, said: "Power to her".
"Meka is a great friend of mine, a fellow Hawke's Bay MP. She always will be a great friend no matter what political party."
Outgoing MP Aupito William Sio said he isn't sure what her decision is or what has motivated it.
"Whatever she does is her decision and I wouldn't characterise it any other way than a decision she has made for herself."
He said he was in contact with Whaitiri on Monday, but "had no idea this is what the news items said she might decide".
"I don't know what she's decided, what's driving that."
He hasn't tried to contact her overnight, but others have tried.
He doesn't believe the wheels are falling off the bus.
Damien O'Connor said he is just getting on with his job and had no further comment.
Minister Deborah Russell, who also sits outside Cabinet, said acting Prime Minister Carmel Sepuloni will hold a media conference later in the day.
David Clark said he hadn't heard from Whaitiri.
"I have seen the news reports, but I haven't got anything to add sorry."
Labour MP Shanan Halbert said he hasn't heard from her.
"I have seen the reports. We will see what happens today, and we will make some decisions from there."
He expects Labour to make comments later in the day on the issue.
National's Michael Woodhouse said it was a jaw-dropping situation and said there must be truth to the speculation as otherwise Whaitiri would have come out and hosed it down by now.
Simon O'Connor believed it was a sign Labour is losing control of its ministers.
"This is not just backbench MP leaving, this is a senior minister. It is quite remarkable. Let's see how Labour handles this one."
Speaking to AM, National leader Christopher Luxon said Labour is falling apart.
"We've gone from Gaurav Sharma to Kiri Allan and Meng Foon to Stuart Nash and now Meka Whaitiri," Luxon said.
"The people that I feel really sorry for are actually the people in the Hawke's Bay because they need a Cyclone Recovery Minister, they've gone through two of them in a very short period of time and things aren't getting done."
On Tuesday night, Mark Mitchell said it's evidence "they're not happy campers" inside Labour.
"The pressure is coming on. I think the polls are starting to move away from them a bit now and this is what happens as the cracks start to appear. And this is big crack without a doubt."
Judith Collins told Newshub it was "people actually escaping that sinking ship".
"Clearly Meka has seen the writing on the wall and there must be something really awful going on in that caucus," Collins said.
