There is growing pressure on the Federal Government to reveal how much revenue the mining tax has raised despite Labor's insistence that doing so is illegal.
The Coalition plans to move a motion in the Senate when Parliament returns next month, demanding the head of the Tax Office provide the Senate economics committee with details of revenue collections from the tax.
The Greens have also written to the Prime Minister, reminding her of her commitment to release those details by January 31.
"The Prime Minister promised transparency, well let's see that transparency," Greens leader Christine Milne told reporters in Hobart.
"If we've got nothing, as we had at the end of the first quarter, then you have to declare it a failure and you have to now fix it to make sure we start getting some of that revenue to invest in education, Denticare and disability." The Australian newspaper reported earlier this week that the Minerals Resource Rent Tax (MRRT) had not produced any revenue for a second consecutive quarter, prompting the Coalition to demand the Government release details of revenue collections.
But Treasury advice provided to the Government, and shown to the ABC, backed the Tax Office's view that releasing the data would breach the privacy provisions in the Taxation Administration Act.
"This is because it was obtained by the ATO for the purposes of a taxation law and relates to the affairs of a small number of entities and is 'reasonably capable of being used to identify' some or all of the entities concerned," the Treasury minute stated.
Shadow assistant treasurer Mathias Cormann says he has since received advice from the Clerk of the Senate which shows that the privacy provisions in the tax laws do not prevent the information being provided to Parliament.
"Once that committee of the Senate has obtained the information on how much or how little the mining tax has raised, that committee would be entitled to publish that information," Senator Cormann told ABC News.
He says it is a "ridiculous" situation to have a tax where the revenue collections are kept secret.
"The people of Australia are entitled to know whether the mining tax, which has been a very contentious tax for some time now, has raised any revenue at all, and if so how much." Senator Cormann says given the Greens' voting record, he expects them to support his push for the details to be made public.
A spokeswoman for Acting Treasurer Penny Wong says it is a matter for the Senate to decide how it responds to the Clerk's advice.
"We are acting on Treasury advice that is based on guidance from the ATO, which has been confirmed by the Australian Government Solicitor," the spokeswoman said.
Transparency When the MRRT legislation was being debated in the Parliament, Ms Gillard wrote to the then Greens leader Bob Brown promising "transparency" in how the tax was performing.
"In order to provide confidence as to how the tax is playing out and the precise ways the revenue is collected, we will review resource rent taxes in order to publish monthly updates on revenue collections from these taxes," Ms Gillard wrote.
Senator Milne has reiterated her belief that the mining tax needs changing to remove "loopholes" in the legislation.Â "I have said again to the Prime Minister, the Greens are prepared to work with her to block the loopholes so that we start to generate revenue from this tax in order to really be able to fund education, national disability and the like," she said.
Ms Gillard renegotiated the mining tax with the three biggest miners - BHP Billiton, Rio Tinto and Xstrata - soon after she took over from Kevin Rudd as Prime Minister.
Mr Rudd said this week the revenue collections were "certainly disappointing" but added that people should wait until there was full year's numbers before making a final judgment.