The Government should heed the Waitangi Tribunal's recommendation to halt the partial privatisation of state-owned energy companies or face expensive litigation, say opposition parties.
The Maori Council had sought an urgent direction from the tribunal against state asset sales, arguing Maori have an ongoing relationship with freshwater resources, including rivers, lakes, springs, and geothermal areas and they have rights equivalent to property rights to them.
The Crown argued that there cannot be ownership of freshwater resources but people can have rights to them.
The tribunal said on Monday that the Crown shouldn't begin the sale of shares in any of the mixed-ownership model companies until it has completed a report on its inquiry into water rights in September.
Labour leader David Shearer says National's insistence on ploughing ahead with the asset sales in the face of the Maori claims exposes taxpayers to huge financial risk.
"If this goes to court, taxpayers will foot the bill while private investors enjoy the profits," he said.
Greens co-leader Russel Norman says the Government must "uphold the mana of the Waitangi Tribunal" and not proceed with asset sales until it makes its full findings.
"Pressing ahead now would invite expensive litigation from the Maori Council and iwi," he said.
Tribunal rulings are not binding on the Government but Prime Minister John Key says it will consider the report carefully and seek advice from a number of Government agencies, including Crown Law and Treasury.
"We also gave a commitment that we'd discuss our response with the Maori Party and they'll obviously be discussing with us their response," Mr Key said.
"We want to act in good faith and let the process run its course, but in the fullness of time we will respond to the Waitangi Tribunal."
The Government wants to sell 49 percent of Mighty River Power, Genesis Energy, Meridian Energy and coal miner Solid Energy.
NZN