Iwi opponents to ironsand mining say the Crown is once again trying to restrict its rights over the foreshore and seabed.
Trans-Tasman Resources has been in the Supreme Court this week in a bid to get previous decisions against it overturned.
The offshore mining company's case argues that the Court of Appeal got it wrong on aspects of environment and Treaty law.
Meriana Johnsen has covering the Supreme Court case and speaks to Susie Ferguson.