Labour leader Phil Goff is expected to announce on Tuesday he is stepping down and the party caucus will let him decide when a successor should take over.
The feeling among MPs is that Mr Goff ran a good campaign and the handover should be orderly, as it was when Helen Clark resigned the leadership after the 2008 election.
Mr Goff is likely to want the caucus to have at least a few weeks to weigh up the options.
The frontrunners are senior MPs David Cunliffe and David Parker.
Mr Cunliffe, the party's finance spokesman, has the highest profile but there's understood to be concern in the caucus over the way he handled the costings of the party's policies.
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They weren't announced until late in the campaign - and after Mr Goff was floored in a televised debate with Prime Minister John Key who taunted the Labour leader with "show me the money".
Mr Parker, Labour's economic development spokesman and chief policy architect, has let it be known that he wants the top job and could run on a ticket with Grant Robertson as his deputy.
He's popular in caucus but the Labour line up has changed significantly.
There are 34 MPs compared with 43 it had after the last election and four of them are new.
And one seat is still undecided.
Brendon Burns won't know whether he's still MP for Christchurch Central until special votes have been counted and announced on December 10.
Mr Burns and National's Nicky Wagner gained an equal number of votes on election night.
Mt Albert MP David Shearer has also been spoken of as a potential future leader, but has kept fairly quiet on the matter.
NZN / 3 News