A collective of Waikato hapu says it could take a separate legal case over the Crown's treatment of the Treaty of Waitangi in the water claims battle.
Pouakani is seeking freshwater rights recognition, alongside the Maori Council.
Both are making an appeal after losing a High Court bid to delay the sale of state owned hydro power stations.
Pouakani chairman Tamati Cairns says Te Tiriti o Waitangi is being disregarded and minimised.
He says the founding document is fundamental to the decisions made by the Crown.
Mr Cairns says it would be illegal to make decisions without addressing the Treaty.
But the High Court judgement released on Tuesday said the Crown's proposal to sell shares in power stations is not inconsistent with the principles of the Treaty.