The left will unite and field only one Super City mayoral candidate, giving Len Brown first chance to go for the top job ahead of rival Mike Lee.

Mr Lee has indicated he will not join the race and split the vote if Mr Brown's campaign gained traction before next year's election.

The scenario would set up what Labour insiders call their "dream team" of the pair working as mayor and deputy, with Mr Brown's wide appeal complemented by Mr Lee's technocratic grunt.

Mr Lee told the Labour conference: "I am absolutely confident there will only be one left-wing candidate".

He made the comment after being asked if the left would have the discipline to field only one candidate.

Mr Lee said this did not mean he was standing aside for Mr Brown.

Labour insiders said Mr Lee was implying that he would not enter the race if Mr Brown was doing well, but with the election still a year away did not want to rule himself out.

Insiders say Mr Lee could run for one of the ward seats, with an agreement that if he were elected Mr Brown would appoint him deputy mayor.

Mr Lee is chairman of the Auckland Regional Council, and Mr Brown is Mayor of Manukau City.