Labour leader David Cunliffe says the party will not make a coalition agreement before the election.
He has rejected a proposal from the Greens to campaign on a platform of a 'Labour Greens' or even a 'Green Labour' government.
Mr Cunliffe told Morning Report it is very likely Labour will work closely with the Greens, but he does not want to make a commitment at this stage, especially if it could hinder relationships with other parties.
He said Labour would consider working with New Zealand First, the Mana Party and the Maori Party.
Mr Cunliffe also said comments by New Zealand First leader Winston Peters about post election arrangements were just posturing.
Mr Peters has asked why he would want a deal if Labour and the Greens can't get their act together now.
However, Mr Cunliffe said Mr Peters is just positioning his own party.
Earlier, Prime Minister John Key said whatever Labour and the Greens might be saying now, they will form a government together after the election, if they are able to.
He said he has no doubt the two parties will work together, if the numbers fall their way.