Greens co-leader Russel Norman is facing a challenge for the party leadership from a low-ranking Greens candidate.
David Hay, who is 16th on the Greens' list, said Dr Norman had done a great job but he had been co-leader for six years and a change was needed.
It is the first time Dr Norman has been challenged for the top spot.
In a statement released this morning, Mr Hay said: "There is a real possibility that the Greens will be in government after the next election, and the party needs to be putting its 'A' team forward."
Mr Hay, a policy analyst at the Auckland Council, said the party had too few MPs in Auckland and one of its leaders should be based there.