Federal Treasurer Wayne Swan has refused to rule out the introduction of a resources rent tax, following reports that the new tax will raise at least $5 billion a year.
The government's tax reform plans will become clearer this Sunday, when the long awaited Henry Tax Review will be released publicly.
There has been persistent speculation in recent months that the review recommends aresources rent tax, adding to the $7 billion already being paid by miners in state royalties.
While the big players in mining have named the additional tax as the "worst case scenario" and a "thermo-nuclear option", federal treasurer Wayne Swan remained coy when pressed on the issue over the Anzac Day weekend.
Asked if the review would include the speculated new mining tax, he said "I am not going to speculate about any of the detail in that report. I'm sure we will read a lot of speculation about that review, much of it will be wrong."
"The independent tax inquiry is about building a simpler and fairer tax system to build a stronger economy... and it will be published next Sunday for everybody to see and talk about and to analyse, and I hope as a country we have a mature discussion about its recommendations," Mr Swan said.
Mr Swan said the mining companies who were referring to the tax strategy as a worst case scenario hadn't seen the recommendations or the review and would have to wait until they see the recommendations.
"I'm not ruling anything in or out," Mr Swan said.
However, media surrounding the Henry Tax Review has speculated the tax would be applied to all mineral and onshore gas projects and could cost BHP Billiton and Rio Tinto up to $5 billion.
Press speculation has also tipped the Henry Tax Review, conducted by treasury secretary Ken Henry, as being aimed at offsetting the rising public health budget requirements with the increased tax for miners.
It is also rumoured that states losing out on GST through the Commonwealth Grant Commission's GST distribution recommendations would possibly have a portion of the resources rent tax funnelled back to them in lieu of the lost GST funds.
