THE mining magnate Andrew Forrest has accused Julia Gillard and Wayne Swan of cutting a deal with big mining companies to get rid of Kevin Rudd.

As the war of words escalated yesterday, Mr Forrest also confirmed his company, Fortescue Metals Group, would challenge the minerals resources rent tax in the High Court.

Legal challenge ... Andrew Forrest confirmed that his company would take the Minerals Resources Rent Tax to the High Court. Credit:Nic Walker

This week, Mr Forrest repeated claims he first made two years ago that he and Mr Rudd were on the cusp of reaching a settlement over the resources super profits tax when Mr Rudd lost the leadership to Ms Gillard.

In a statement yesterday, Mr Forrest went further, saying that despite the advanced nature of the negotiations, Ms Gillard and Mr Swan cut a separate deal behind the scenes with one minerals company, understood to be BHP Billiton.