The Maori Council says it's shocked that the Government has asked the Waitangi Tribunal to rush through a report on its water rights inquiry.
Two ministers have written to the tribunal, asking for its recommendations and reasoning by 24 August.
They argue that for the Crown to go ahead with the sale of shares in the hydro generator Mighty River Power, the Government would need to make decisions by the first week of September.
Maori Council deputy chair Rahui Katene says it's stunning that the Government should write to the tribunal, giving a deadline.
She says if a party in a court case were to write and make requests to the judge, they would be held in contempt of court - and she says there is no difference in this situation.
Before Thursday's request from the Government, the Waitangi Tribunal had said it would deliver a full recommendation in September, following the first phase of its inquiry into water rights.
Meanwhile, the Maori Party is to meet with Maori water rights claimants on Monday - only hours ahead of the party's meeting with Prime Minister, John Key.
Maori Party co-leader Pita Sharples says his caucus is meeting with Maori who have an interest in the issue of water rights.
He says he and Tariana Turia will be meeting with Mr Key on Monday, and want to talk to Maori with an interest in water to gauge their views before hand.