Maori Council lawyer Felix Geiringer this morning challenged John Key's claim no one owns water and said the Prime Minister had misled the public on that point.
Justice Ronald Young is hearing in the High Court at Wellington the challenge to the Government's plan to partially privatise Mighty River Power next year taken by the council, the Waikato River and Dams Claims Trust and the Pouakani Claims Trust.
The council argues it is unlawful for the Government to sell shares in the company because that would affect the Government's ability to make redress for any Maori ownership claims over the Waikato River and other water bodies.
But Mr Key has dismissed the council's claims a number of times, saying his Government's view was that under common law no owned the water in rivers, lake and other water bodies.
But this morning Mr Geiringer said Mr Key was wrong, and his statements were an "error of law" and "meaningless".