The leader of the Western Australia (WA) National party Brendon Grylls wants to increase the iron ore tax from A$0.25 per metric ton (mt) to A$5/mt charge for iron ore miners BHP Billiton and Rio Tinto. He said it could raise $7.2 billion over four years to return the state budget to surplus and help pay down debt.

A spokesman for Resources and Northern Australia Minister Matt Canavan said any proposal regarding a royalty scheme was a matter for the WA government. “However, it would be of concern if any proposal was to potentially discriminate against or target particular companies, impact long-standing royalty arrangements and in turn, reduce certainty for the sector,” the spokesman said, according to Australia’s ABC.