The Tongan Advisory Council says Prime Minister John Key is on another planet if he thinks Maori and Pacific Islanders will not struggle to be elected to Auckland's super-city council.
The Race Relations Commission has said the super-city will not do enough to ensure Maori and Pacific Islanders have a say.
But Mr Key says ward-based elections for the council will ensure diversity.
Tongan Advisory Council chairman Melino Maka says Pacific Islanders will be worse off under the super-city.
He says both Maori and Pacific Islanders need dedicated seats on the new council.
Mr Key, speaking at Saturday's Pasifika Festival, said the turnout at the festival showed there was a strong Pacific voice. He said ward-based elections would allow people to choose candidates that represent their part of Auckland.
Labour MP's bias claim
Labour Party MP Carmel Sepuloni says some Auckland City councillors and the National Party worked to court the Pacific Island vote by trying to exclude opposition MPs from the Pasifika Festival.
The Tongan MP says that at Saturday's Pasifika Festival she went up to the stage to say a few words to her community. But organisers told her they were under instructions not to allow any politician on stage except Mr Key or Auckland Mayor John Banks.
Ms Sepuloni says the council and National Party sought to use the event as a platform for themselves.
The council says no instruction whatsoever was given to prevent Labour MPs from going up on stage.