Grylls, the former leader of Western Australia’s National Party, is said to be challenging current leader Terry Redman today for his old job.

At the centre of his comeback plan is reportedly a $A5 per tonne mining tax on BHP and Rio.

According to reports, the tax would not apply to rival miners like Fortescue Metals Group or Roy Hill Holdings.

Chamber of Minerals and Energy of WA CEO Reg Howard-Smith said the royalty would be bad news for WA.

“While Mr Grylls’ short-sighted plan to tax BHP Billiton and Rio Tinto is only in its infancy, any suggestion it would become a future policy of the National Party is strongly opposed by CME and the resources sector,” he said.

“Not only would the plan be detrimental to Western Australia’s international economic standing but competitors would revel in the news.”

Rio did not respond to requests for comment, and BHP had no comment.

However, a BHP spokesperson noted that the miner had made a significant investment in WA.

“To ensure our business remains globally competitive, a stable and predictable tax regime is critical. 

“We appreciate the stable and consistent investment environment the Western Australian government has offered over many decades.”

The leadership challenge is due to occur today.