The Maori Council is filing Waitangi Tribunal claims on Tuesday that could stall the Government's plans to sell shares in State energy companies.
The council claims the Crown has stripped Maori of their ownership of fresh water and geothermal resources, without consent or compensation.
It is asking the tribunal to recommend a halt to the Government plan to sell 49% of four energy companies, until a settlement is negotiated.
The claim is being lodged in the name of Maori Council chair Sir Graeme Latimer and 11 hapu groups from the Far North to Manawatu - on behalf of all Maori.
Sir Graeme's spokesperson, Maanu Paul, says the claimants do not want to disrupt the Government's economic programme but they believe Maori have a legitimate claim to a share in the power companies.
The Maori Council is also asking the Waitangi Tribunal to recommend that legislation paving the way for partial asset sales include a clause protecting Treaty rights.
Resource management academic Maria Bargh says the claim reflects long-standing concerns about water rights amongst Maori.
Dr Bargh told Morning Report Maori have been raising the issue since the 1800s, though the Crown has refused to discuss it.
She said the Crown is being devious by claiming no one owns water, because people constantly trade water rights.
Environment Minister Nick Smith says he is surprised a claim is to be lodged with the Waitangi Tribunal over freshwater.
Dr Smith told Morning Report that the Maori Council has not been to see him at all since he has been Environment Minister and he is surprised that the first action by them is to lodge a claim with the Waitangi Tribunal.
Earlier, he said the Government is already working with other Maori on improving the management of freshwater and the Maori Council running off to the courts was not constructive.
The Prime Minister says it remains to be seen whether Maori claims over freshwater will slow the Government's plan to sell shares in four State energy companies.
The claimants say Maori have a legitimate claim to shares in the energy companies and they will go to court if necessary to back it.
They are also asking the Waitangi Tribunal to recommend the retention of a clause in State Owned Enterprise legislation, protecting Treaty rights.
John Key says he would be surprised if the claim affected the sale process.
Finance Minister Bill English has acknowledged the Government was always prepared for the possibility of a Treaty claim around its partial asset sales programme.
Mr English says the partial sales have been discussed for 12 months now, and the Government is getting on with the job.
But he says there is still time to deal with any issues people raise.