A Labor MP insists there is no chance a revived mining industry campaign about the resources rent tax could claim another prime minister's scalp.
The Minerals Council of Australia has run full-page advertisements in newspapers today warning the Federal Government not to make changes to its minerals resource rent tax (MRRT).
The tax has raised just $126 million in its first six months of operation against a full-year forecast of $2 billion.
The Greens and other crossbench MPs are urging the government to close loopholes in the tax, including offsetting state royalties mining companies pay against their MRRT liabilities.
Labor MP Graham Perrett says the government isn't scared about the industry's revived campaign.
"Bring it on, the harder fought the better won," he told reporters in Canberra.
Asked if a new campaign by miners could claim a second prime minister's scalp, he said: "Rubbish, not a chance."
An industry campaign against the dumped super profits tax led to the demise of Kevin Rudd in June 2010.
Mr Perrett said the structure of the MRRT was perfect.
"We just can't have a state jack-up royalties time and time again and the commonwealth taxpayers give reimbursement," he said.
"That's not an arrangement that we can sustain forever."
He denied Labor MPs were divided over the design of the tax.
Labor MP Rob Mitchell was not "worried at all" about the prospect of a new campaign from miners.
"Julia Gillard is the prime minister and will remain our leader," he told reporters.
Opposition mining spokesman Ian Macfarlane said the government was in disarray over its mining tax.
"This is a major betrayal of the mining industry," he said of speculation the government would back away from its agreement to offset royalties.
Treasurer Wayne Swan got "skinned alive" during the negotiations with the three big miners BHP Billiton, Rio Tinto and Xstrata in mid-2010.
"He went from being a swan to a plucked duck in one day," Mr Macfarlane said.
Australian Greens deputy leader Adam Bandt said he was concerned by reports that the big miners had hoarded credits and won't have to pay the MRRT for years.
"This needs to be fixed before the budget," he told reporters.
There was enough support on the crossbench to support his private member's bill that aims to plug the state royalties loophole, Mr Bandt said.
Mr Bandt said it was clear billionaire Gina Rinehart and the big miners had Tony Abbott "in their pockets".
"Increasingly, it's obvious they have Labor there as well," he said.
Mr Bandt said Labor needed to have the guts to stand up to big miners.
"They're quite happy to take the big stick to single parents," he said, referring to recent welfare cuts for sole parents.
"Labor is taking more money off single parents this year than it has raised with the mining tax."
Nationals leader Warren Truss questioned how independent MPs Rob Oakeshott and Tony Windsor could now claim the mining tax deal was a "dud" when they voted for the legislation.
"It beggars belief they refuse to accept any responsibility for backing the deceitful and failed policies of Julia Gillard and now want to pretend none of it is their fault," he said.
"Mr Oakeshott's protest that he feels 'duped' are typical of a bloke trying to worm his way out of the mess he was instrumental in creating."
It was a bit late for Mr Windsor to be seeking further advice when the MRRT already had proved a flop, he added.