Labour leader Phil Goff is expected to announce today that he will resign before Christmas, giving his party a few weeks to settle on a new leadership team.
The only runners are likely to be Mr Cunliffe and Mr Parker who have now begun building up support in earnest and are likely to openly declare their contest after Mr Goff has announced he will step down.
It is understood Mr Cunliffe has signed up Waikato Hauraki MP Nanaia Mahuta to run on his ticket as his deputy. As a Maori woman who represented a largely rural electorate, she would act as a counterbalance to Mr Cunliffe.
It is a canny move that may test others in Labour's Maori caucus, such as Shane Jones and Parekura Horomia, who were expected to support Mr Parker.
Mr Parker will run on a ticket with second term MP and campaign spokesman Grant Robertson. The team is understood to have the backing of the current leadership team, although Mr Goff and Annette King are unlikely to openly endorse it.
Some are understood to be arguing Mr Robertson should stand as the leader on that ticket as a "fresh face'' with Mr Parker as his deputy. However, he is relatively inexperienced and there are concerns about whether the middle-class New Zealand that Labour needs to win the support of was ready to accept an openly gay MP in such a position.
So far the contest appears to be close and could come down to the four newcomers to the caucus. If the caucus is too fractured, there is also a risk that it will not unite behind the new leader.
Mr Cunliffe's main supporters include Lianne Dalziel, and Charles Chauvel and Moana Mackey. It is understood he has offered them the whips' jobs if he wins the contest. Others likely to side with Mr Cunliffe include Ruth Dyson, Sue Moroney and most Auckland MPs, including Rajen Prasad, Darien Fenton, Louisa Wall and Phil Twyford. However his numbers have been weakened by the MPs who did not return to Parliament.
As well as Mr Goff and Ms King, those likely to support Mr Parker and Mr Robertson include Jacinda Ardern, Trevor Mallard, Clayton Cosgrove, Maryan Street, Kris Fa'afoi, Shane Jones, Damien O'Connor, Andrew Little and Chris Hipkins.
Many in caucus are undecided and some MPs said more time was needed to digest the election results and figure out who was best to take the party on.
If there is a widespread call for a slower process at the caucus meeting tomorrow, Mr Goff could be asked to stay on as leader until early February. He is unlikely to agree to stay longer.
The contest has already caused some antagonism. Mr Cunliffe supporters are angered by claims Mr Cunliffe did not support Mr Goff properly during the election campaign. Some have blamed him for not ensuring Mr Goff could use the party's costings in time for a critical debate against John Key.
Mr Jones has ruled himself out of contesting the leadership, and others such as David Shearer and Mr Little are too inexperienced.
If the new team struggles to make an impact for Labour in the polls its caucus is unlikely to wait a full term to replace them, as it did with Mr Goff. If that happens, others such as Mr Jones, Mr Shearer and Mr Little could step up, or Mr Robertson could take over.
- Claire Trevett, New Zealand Herald
