The lawyers for Maori challenging the Government's decision to sell off shares in state-owned power companies say it will be difficult for Maori rights to be recognised after they're sold.
A judicial review sought by the Maori Council and Waikato iwi began in the High Court at Wellington on Monday.
The Maori Council and the Waikato River Trust told the High Court the share floats will breach the Treaty of Waitangi because Maori claims to water have not yet been resolved.
Justice Young queried how Maori rights would be affected, since the Government has only ruled out special shares for Maori in the power companies, not any other water right options.
But the Waikato trust's lawyer, Helen Cull, said the experience of land claimants showed claims must be acknowledged before the assets pass out of state ownership.
"Once it's in the hands of a commercially driven company, the ability of Maori to seek redress is strictly limited and, indeed, becomes another major battle.
Maori Council lawyer Felix Geiringer said it was irrelevant to say the Government could theoretically address Maori rights by changing the law because it might not decide to do so.
"The essence of what's wrong with the decisions according to the New Zealand Maori Council is the absence of steps to protect Maori interests and there's no expressed decision out there saying that nothing along these lines is going to be done," Mr Geiringer said. "What's happening is a positive decision to do these things without taking these steps to protect."