A party insider told the Herald Mr Davis would have had to be in the top 10 to ensure a seat in Parliament. His ranking of 18 would blunt a Mana tactic of asking people to vote for Mr Harawira because Mr Davis had a safe list spot and would be an MP anyway.
Labour's list of 64 candidates includes 30 men and 34 women. A further 21 candidates - 16 men and five women - are not on the list and standing only for electorates. They include senior MP Trevor Mallard, who took himself off the list to improve Mr Davis' ranking.
Although Mr Mallard does not rely on the list for his seat, his decision appears to be due to concern that Mr Davis would be ranked below more women to ensure the 45 per cent ratio for women was maintained throughout the list.
Sitting MPs Mr Mallard, Kris Faafoi, Clare Curran, Ruth Dyson and Rino Tirikatene are all standing only in their respective electorates.
Mr Faafoi said he wanted to concentrate on being the MP for the Mana electorate, but added that if that helped Mr Davis return to Parliament, then all the better.
Labour will have to win about 32 per cent of the party vote to bring in any new candidates.
Among them are women's affairs policy analyst Priyanca Radhakrishnan, Dr Rachel Jones from Tauranga, and former TVNZ presenter Tamati Coffey, who is standing in Rotorua.
MP Carol Beaumont has dropped to number 27 and faces losing her seat unless Labour wins more than 33 per cent of the party vote.
Leader David Cunliffe said he was "delighted at the fantastic array of talented candidates who have made it on to our list".