The court gives Maori claimants a small bone by rejecting findings last year in the High Court that the cabinet decision to sell a stake in MRP could not be judicially reviewed.

Partial privatisation of Mighty River Power will not impair to a material extent the Crown's ability to remedy any Treaty breach in respect of Maori interest in the river.

Prime Minister John Key says cabinet could have passed an Order in Council today to proceed with the sale, but it would have been "churlish" to do so.

A decision by next Monday on the Maori Council's appeal to halt partial privatisation of Mighty River Power may not be met.

Professor Andrew Geddis says the High Court’s decision was “a robust one and I would be surprised to see it overturned”.