Deputy Prime Minister Barnaby Joyce says he understands the aim of a proposed new tax on Rio Tinto and BHP Billiton's iron ore that his own boss has described as "troubling".
But he doesn't want to get involved in a fight between his Nationals Party and the Liberals in Western Australia.
The WA Nationals have proposed increasing a royalties charge from 25 cents to $5 per tonne of iron ore for the two major mining companies, to help fix the ailing state budget.
But Liberal Premier Colin Barnett has rejected the idea.
"The good thing about (WA Nationals leader) Brendon Grylls is he's always trying to do what National Party people do and get a better deal for people in regional areas," Mr Joyce told ABC TV on Sunday.
However, he stopped short of taking a side in the state-based argument.
"I've got enough fights of my own, I don't need to be part of theirs," Mr Joyce said.
"Whether this is the right way or the wrong way, well it's a discussion for Western Australia."
Prime Minister Malcolm Turnbull is worried the plan could damage investment.
"It obviously sends a very troubling message to mining companies and other people considering making long-term investment," he told The West Australian newspaper on Saturday.
