Brown told Channel 10’s Meet the Press on Sunday the Greens will support the tax the government went to the polls with – a 22.5% rent tax, to be levied only on iron and coal.

He said the Greens remained in favour of a higher levy on the mining industry, but accepted that the headline rates negotiated between Prime Minister Julia Gillard’s government and the big three miners would go forward into legislation.

“The position of the Greens clearly in the election campaign on that – yes, we do want the original Treasury formula which the Rudd government took up of a 40 per cent tax on super profits,” he said.

“That said, we will take the government's alternative. Prime Minister Gillard went to the election with a formula which is effectively a 22.5 per cent tax, but only on coal and iron ore.”

Brown said the Greens would use their newfound alliance with Labor to seek “improvements” in the tax, but the headline rates would not be a part of those negotiations.

“We will talk with the government to see if there is improvements to be gotten out of that because talks always can lead to improvements, but I would expect that that basic rate is the one that will apply,” he said.

While Brown’s comments will allay the concerns of some sectors of the mining industry that the Greens would seek to expand the reach of the tax into other industries, his comments indicated the minor party will use its influence to force greater scrutiny of major mining and resource projects.

Brown singled out the $30 billion James Price Point gas plant in Western Australia for special mention, but said his political party would seek to wield its newfound influence over a range of projects.

“Yes, we will be talking with the ministers about issues which are important to the electorate. As far as the James Price Point site in the Kimberley for a gas plant, very contentious, where the premier of Western Australia is now riding roughshod over the indigenous people with a compulsory purchase, there are alternatives to that site and they should sensibly be looked at,” he said.

“That alternative, those alternatives are one we will be expecting the federal government to explore.”