Jacinda Ardern resignation: Labour MPs jockey for position in bid to become NZ's next Prime Minister

The day after the Prime Minister's shock resignation, she says she has no regrets about the decision.

As Labour MPs jockeyed for position in a bid to become New Zealand's next Prime Minister, Jacinda Ardern on Friday said she had the best night's sleep in a long time.

"I have to admit I slept well for the first time in a long time last night but still a range of emotions. I feel sad but also I do have a sense relief," Ardern said. 

Asked by Newshub if she still thinks she has made the right call, Ardern said: "Yes I don't doubt it, even though I am tinged with sadness I don't doubt the decision".

Her decision leaves Labour leaderless, but the relaxation mode is contagious - even among potential PM candidates. 

Newshub caught up with a casual Chris Hipkins out for a walk in a tracksuit. He wouldn't say if he wants the top job.

"I'm not gonna get into that."

Later at Napier airport, Hipkins said it would be "very premature" to consider him the next Prime Minister.

"I'm not ruling [running for the leadership] out but I'm also saying I'm absolutely committed to making sure that as a team we reach a consensus if we can do that... I'm saying we should work together as a team to reach a consensus."

Labour's Michael Wood was also out in Napier in mufti working the phones. But he wouldn't tell us who to. 

"It would be rude of me to talk about private conversations I've had with anyone on the phone."

He also wouldn't rule anything in or out. 

"That's going to be a collective and internal process. I'm a team player," he said.

"We have all agreed that we would do this as an internal team process. I don't think politicians ever do themselves or their parties or the country any favours by playing these things out in public."

Frontbencher Megan Woods has been a little clearer, indicating to Newshub she's out. 

"I think everyone knows I have never really shown leadership ambition".

Woods, Labour's campaign chair, said she is "keen to run our campaign".

Labour MPs flying out of Napier from the crack of dawn clammed up about who they'd be backing. Phil Twyford, David Clark, Aupito William Sio, Stuart Nash, and Kelvin Davis were among those who refused to divulge any details. 

But the Māori caucus will meet on Saturday to determine who that bloc might back.

"We'll be meeting as a group in terms of a Māori caucus. Because this is incredibly important. We are talking about the Prime Minister of our nation. We want to play a part," said Willie Jackson.

"As co-chair of the Māori caucus, we do support our Māori colleagues," MP Rino Tirikatene.

He wasn't sure if colleague Kiri Allan will run and said he was still considering his position. 

And in a break from the caucus line, MP Ibrahim Omer revealed he tried to twist Deputy Prime Minister Grant Robertson's arm. 

"I spoke to him. I told him if he could ever change his mind, but he said that he made a decision," Omer said.

The Prime Minister - Robertson's BFF - agrees, saying on Friday that his mind is made up.

"His decision has been made," said Ardern. "I have deep respect for Grant Robertson." 

"He's a friend, he's a colleague. I see day-in day-out the all he gives the job and he wants to continue giving his all in the roles he has, but he's ruled himself out for this one and I respect him."

She's ruling out showing support for any successor. 

"I intend to remain neutral."

The caucus is so locked down the public may not even get to know who the candidates are.

Phil Twyford said on Friday that he doesn't think anyone will publicly declare beforehand. 

It raises the question of whether the Prime Minister should have just called a snap election and let the public vote.

"No, obviously I'm not the first Prime Minister to stand down, and practice and convention has always been in those scenarios a transition to a new leader and therefore a new Prime Minister," Ardern said.

"Elections are incredibly disruptive. There was no need for one."

Either way, come October, Kiwis will decide if the Prime Minister Labour picks, is their pick too.