Labour has delayed the release of its list after broadcaster Willie Jackson flew to Wellington to discuss his ranking.
The moderating committee will hold another meeting tonight to discuss Jackson's placing, before an announcement is made tomorrow morning.
The party had been due to announce the list today. A spokesman would only say "discussions are ongoing".
Jackson, a former Alliance MP, was considering standing for the Maori Party, but that changed after being approached by Labour leader Andrew Little to stand on Labour's list.
In announcing Jackson's candidacy in February, Little said he would be "backing Willie to have a high list position" and "am confident he will be joining our ranks after this year's election".
Some members and MPs were frustrated that Little's promise of a high list spot for Jackson went against the drive to get more women into Parliament for Labour. The party has committed to at least 50 per cent of MPs being women, and its ruling council must consider that aim when selecting the list.
Little is not contesting an electorate and is number one on the list.
The overall percentage of party vote and number of seats won determines how many candidates are elected from a party's list.
Current MPs reliant on the list include Foreign Affairs spokesman David Parker, veteran and Speaker aspirant Trevor Mallard and Raymond Huo, who returned on the list after the Mt Albert by-election.
On Sunday Labour list MP Sue Moroney announced her retirement from politics, citing her unelectable position on the list. Labour had already confirmed its 71 candidates and Moroney's reaction to her demotion means it will need to hold a new selection in Hamilton West, where she was to stand.
Labour's six MPs in Maori seats have opted to go off the list and stake their re-election on winning their electorate. Those seats are unpredictable because of a newly-formed alliance between the Maori Party and Mana and the Kingitanga Movement's endorsement of the Maori Party.
Labour's Kelvin Davis could face a strong challenge from Mana's Hone Harawira in Te Tai Tokerau, where the Maori Party has agreed not to run a candidate.
Labour will feel it has a chance in a couple of marginal seats, including Maungakiekie where Priyanca Radhakrishnan is standing. National has selected Auckland councillor Denise Lee after Sam Lotu-Iiga's retirement from politics, and Labour's chances could be complicated by the Green Party's decision to run the high-profile candidate Chloe Swarbrick in the electorate.
In Ohariu, one of the closest races in the 2014 election, new Labour candidate, former Police Association head Greg O'Connor, could unseat long-serving United Future leader Peter Dunne. The Green Party has pulled its candidate to give Labour a clear run.
Christchurch Central could also be close, with Labour's Duncan Webb aiming to upset National Minister Nicky Wagner.
Auckland Central was the closest seat in 2014, but Jacinda Ardern has left and National's Nikki Kaye has risen in profile following her breast cancer battle and promotion to Education Minister. Employment lawyer Helen White will stand for Labour.