Prime Minister John Key may ignore any Waitangi Tribunal recommendation to delay the sale of Mighty River Power, but the tribunal's opinion would be "persuasive" in further court action to halt the sale, the Maori Council says.

The tribunal is hearing an urgent case from the council and several other claimants who say the Government's partial sale of Mighty River Power should be halted until Maori rights over freshwater and geothermal resources are decided.

As the hearings, attended by about 200 Maori from all over New Zealand, started yesterday morning, Mr Key said that even if the Waitangi Tribunal found Maori held interests in water, the Government would not have to accept the decision.

"We could choose to ignore what findings they might have - I'm not saying we would, but we could," he said on TVNZ's Breakfast.


But at Lower Hutt's Waiwhetu Marae, where the tribunal is sitting, Maori Council co-chairman Sir Eddie Durie, a retired High Court judge, said the council would not let the matter lie if Mr Key ignored a tribunal recommendation in favour of the claims.

"Yes, we do have to look at going to the Court of Appeal," Sir Eddie said.

While the Government is understood to have expected court action and is said to be confident of its position, Sir Eddie said the Court of Appeal would take into account the tribunal's recommendation.

While not binding on the court, any recommendation "is nonetheless persuasive as to facts", he said.

Sir Eddie said Mr Key's comment about possibly ignoring the tribunal was an "unfortunate way to put it".

"Maori have developed a good relationship and a lot of confidence with governments because of their willingness to address it [the Treaty].

"The concern I have as a lawyer is that when the Government has a law on the books that says there is a tribunal which will advise the Government on matters relating to culture and the Treaty, before decisions are made it's indicating it's not going to listen to that body.

"That's like turning your back upon the law, and that's a pretty heavy thing to do, especially for our young people when we are asking them to observe the law ... I think it's a very bad message to send to people."