Labour's latest leadership hopeful admits he may be the underdog but his entry could throw the contest wide open if he can persuade enough MPs he is the clean break the party needs to get back on track.
Andrew Little will go up against Grant Robertson and David Cunliffe while David Parker and David Shearer are still possible late entries before nominations close on Tuesday.
Several Labour MPs are still waiting to see if others put their names in before deciding who to back, but Little is likely to get at least six or seven MPs. Those who could opt for Little include the likes of Iain Lees-Galloway, Kelvin Davis, Rino Tirikatene, Damien O'Connor, and Mr Parker and Mr Shearer if they do not stand themselves.
Mr O'Connor, who infamously described Labour's list ranking committee in 2011 as "self-serving unionists and a gaggle of gays" said he would not make a decision until all candidates were known.
"The challenge we face as a party is that there's no clear, natural leader as was the case with Helen Clark. And that will inevitably lead to ongoing differences of opinion as to who is best to be the leader."
He believed Labour's new system of electing the leader by giving members and affiliated unions a vote should be revisited.
EPMU secretary Bill Newsom said the union will decide whether to recommend a candidate after nominations close next Tuesday. "But ... there has to be a strong possibility of my union endorsing Andrew."
Mr Little could also get strong backing from the Dairy Workers' Union which is now led by Chris Flatt, who was Labour's general secretary under Mr Little before 2011.
Grant Robertson acknowledged Mr Little's union background would help him but did not believe his own chances were reduced.
Mr Cunliffe was not commenting yesterday. Labour uses a preferential voting system under which the lowest ranked candidate is knocked out until one gets more than 50 per cent support.
Mr Little denied he was entering simply to position himself as deputy, saying he had already lost one election this year and "I'm in this to win".
A former Labour MP who asked to remain unnamed questioned whether Mr Little had sufficient parliamentary experience.
Mr Little said leading the EPMU and as Labour's party president meant he was well placed to heal obvious strains between caucus and the members.
"I've decided to back myself and the skills and experience I know I have and they are crucial for Labour at this time."
He has also promised an overhaul of Labour's policies, saying they had confused voters, many of whom were "scared off" voting for Labour.
Mr Little lives in Wellington, in the Rongotai electorate, which has long been held by Annette King and is likely to go to Little when King leaves.