Tensions have emerged between the West Australian Liberals and Nationals over plans to rein in the lucrative Royalties for Regions program.
Just two months out from the state election, the Nationals have declared neither of the major parties can be trusted to deliver the multi-billion dollar scheme.
It comes after the Liberals announced plans to tighten spending under the program, declaring they would not tolerate their conservative allies treating it "like a slush fund to throw money around for purely political purposes".
The opposition's regional development spokesman Steve Thomas has promised that any Royalties for Regions spending under a Liberal government would be matched by savings.
"When the price of iron ore is high and the state is making billions extra in royalties it is easy to throw money around," he said on Tuesday.
"But when the price goes back to its normal long-term average the pressure on the budget will be immense and the very future of the program will be threatened.
"To that end, I expect National Party promises from the Royalties for Regions fund to be matched by savings as well, or they are simply adding debt and deficit and cost shifting like Labor in reverse."
Nationals leader Mia Davies said both major parties had ripped money out of the fund to bankroll other commitments while in government.
"Regional voters deserve better than the two major Perth-based political parties pretending they care about Royalties for Regions just before an election," she said.
The Nationals made the Royalties for Regions program, capturing 25 per cent of the state's resource royalties at the height of the mining boom, a condition of partnering with the Liberals to form government in 2008.
A major inquiry in 2018 by former Treasury boss John Langoulant was scathing of the former government's financial management, finding that royalties had been "shovelled" to the regions for projects with no business cases.
The McGowan Labor government is expected to comfortably win a second term at the March poll, having claimed a landslide victory in 2017.