The Maori Council and a Waikato trust have been given leave to go directly to the Supreme Court to fight a lower court ruling against their bid to block the partial privatisation of Mighty River Power.
The Supreme Court has released its decision allowing the "leapfrogging" of the Court of Appeal, saying the council and trust must file their written submissions by January 18 before a two-day hearing at the end of January.
"It will be a challenging opening for the New Year," said the council's lawyer Donna Hall in a statement on Tuesday.
Earlier this month, a high court judge ruled against the bid to halt the government's plan to sell a minority shareholding in the state asset.
The Maori Council and Waikato River and Dams Claims Trust had challenged the government's decision to sell the shares without first ensuring there was a mechanism to recognise Maori water rights.
The council had filed to the Court of Appeal but the Crown asked for it to go directly to the Supreme Court.
The government plans to sell 49 per cent of Mighty River Power between March and June next year. It is the first asset sale in a programme expected to raise $7 billion.
Parliament has already passed a law allowing the companies to be partially privatised, and the High Court's Justice Ronald Young had ruled a decision by parliament can't be reviewed by the courts.