Grylls wants to “introduce a new revenue stream” by raising the A25c production rental under State Agreements with the big two to $5 per tonne.

“The State Agreements have afforded enormous benefits to RTIO and BHP, however they are now out of date and do not reflect modern practices including Singapore trading hubs, contracting, fly-in-fly-out workforces and automation,” he said.

“It is unfair that this production rental that has existed in the original State Agreement has never been changed since it was created in the 1960s.

“The Nationals WA believe that the state and taxpayers have facilitated a huge expansion of the iron ore industry at great cost to our state budget and the big miners are not paying their fair share.

“These two miners have made almost $US140 billion since 2010, and Western Australia has facilitated that.”

Grylls said the new plan will raise $A7.2 billion and return the battered WA budget to surplus.

He said if WA’s share of GST return was to improve, the rental would be reduced or removed.

WA Premier Colin Barnett, State Development and Finance Minister Bill Marmion, and new Mines Minister Sean L’Estrange have publicly said they don’t support the plan.

Grylls said he had met with Barnett to discuss it.

Rio and BHP have slammed the plan.

“Rio Tinto is one of Australia's largest corporate taxpayers and has paid record royalties of almost $11 billion to the Western Australian Government since 2010,” a spokesman for Rio said.

“This has been on top of our $52 billion spend on local goods and services over the same period.

“There are no grounds for a new mining tax in Western Australia.”

They have the support of industry groups the Chamber of Minerals and Energy of WA and the Association of Mining and Exploration Companies.

AMEC CEO Simon Bennison said the industry needed certainty and predictability in public policy.

“The imposition of an extra tax will create a very dangerous precedent and damage Western Australia’s, and Australia’s reputation as a safe and attractive place in which to invest,” he said.

“It is acknowledged that these mature miners have been provided various concessions over the years, however they have been fundamental to the importance of the growth and job creating opportunities within the industry, and the economy over several decades.”

CME CEO Reg Howard-Smith said WA would be at risk of losing its top ranking in the Fraser Institute report.

“What Mr Grylls hasn’t factored in here is the damage this would do to our superior reputation as a world leader for mining investment,” he said.

“At a time when all companies are focused on innovation and lowering production costs to remain competitive, Mr Grylls wants to impose significant additional government charges on two of the state’s major financial contributors.”

WA Senator and federal Minister for Finance Mathias Cormann tweeted that there would be no mining tax under the Liberal Party.