The Waitangi Tribunal has granted urgency to a hearing which will look into the extent of Maori interests in water ahead of the Government's partial sale of state assets.
In making its decision, the tribunal said the claims, brought by a consortium led by Sir Graham Latimer, addressed "policies of national importance."
The Tribunal said: "Against the criteria for urgency, we are of the view that the claimants are likely to suffer significant and irreversible prejudice, that no other remedy is available, and that they will be ready to proceed on an urgent basis."
Mana Party leader Hone Harawira said the Crown must now stop its privatisation programme until the claim is heard.
"If they don't then this issue could well become the Foreshore and Seabed issue of 2012," Harawira said.
"There was a lot of humming and hahing from some iwi leaders. Seems they were happy to take the loss on the state assets as long as they got a private deal on management rights to the water."
The utilities up for partial sale are Genesis Energy, Meridian Energy, Mighty River Power and Solid Energy.
The Government will retain at least 51% ownership, with individual shareholdings limited to 10%
It also proposes selling some of its existing shares in Air New Zealand, while maintaining a majority stake.
The first asset up for partial privatisation will be Mighty River Power, sometime between July and September this year.