Labour's caucus will today vote on whether to endorse Chris Hipkins as the party's leader.
The 34 MPs will gather away from Parliament for the vote, which will take place during the party's first meeting since the confirmation of the final election result.
Labour's constitution requires the MPs to vote on the leadership no later than three months after the election.
Hipkins must receive 60 percent of the votes cast plus one - the backing of 21 MPs - to stay on as leader.
He has indicated he wants to stay in the role, saying on Friday: "It's a job that I enjoy. I've still got a bit of fight left in me, I think there's an important job for Labour to do.
"The Labour Party has always been very good to me. I'm still absolutely committed to the Labour Party."
Hipkins is expected to get the endorsement of his caucus.
Multiple Labour MPs have told RNZ they fully support Hipkins and stressed the need for stability and unity. They suggested this was a view shared by the caucus.
Senior Labour MP Willie Jackson has previously claimed there were one or two MPs in Labour's caucus with leadership ambitions.
"I think most of the caucus are backing him ... I think one or two people have aspirations."
Labour MPs told RNZ they had not been contacted by any caucus colleagues interested in the leadership and trying to get the numbers.
The Labour caucus is also expected to elect new whips, set a plan for the next three years in opposition and dissect the party's dismal election result.
One MP told RNZ the caucus needed to discuss the party's positions on key policies like tax - an issue that clearly divides some members of Labour's caucus. In the lead-up to October's election, Hipkins ruled out introducing a wealth or capital gains tax.
David Parker, who was revenue minister at the time, made no secret of his frustration at Hipkins' decision and relinquished the portfolio, saying it was untenable for him to stay in the role.
Then, during the election campaign, at least two Labour MPs expressed their support for such taxes.
Former Labour MP Sue Moroney told RNZ last month she hoped the party's election loss would galvanise the party to properly reset, rebrand, and "ensure that the public knows what we stand for".
"They actually have to take a long hard look at some of those decisions, and the political management of both policy issues and the management of people that really tripped them up in the last year or so. You just can't pretend that those things didn't happen."
An obvious example is the division over whether to support a capital gain or wealth tax, Moroney said.
"Then they have to build the argument around which of the paths that they've decided they're going to take because while they're in two minds about it they haven't got a hope of being able to explain to the voting public what their view is and why that's their view."