Fortescue Metals Group has lodged a High Court challenge to the Federal Government's mining tax.
Fortescue said it would challenge the Minerals Resource Rent Tax on constitutional grounds.
"We believe we have a good case for challenging the MRRT on constitutional grounds and we look forward to the resolution of these important issues by the High Court," Fortescue chief executive Nev Power said in a statement.
He said the tax gave preference to one state over another, contrary to the constitution.
It also restricted a state's ability to encourage mining, another contravention of the constitution, Mr Power said.Andrew Forrest, Fortescue's chairman, has been a vocal opponent to the MRRT.