The proposed mining tax (MRRT) was criticized as being a mere election ploy by opposition finance spokesperson Andrew Robb.
The fresh attack on the MRRT came after global resources intelligence firm Intierra reported that the new tax would raise only $2.5 billion in the first two years rather than the $10.5 billion that the government had forecast.
The report estimates that just 50 companies would actually pay the tax and so the federal government will not be able to raise the kind of money that it said it would. The spokesman for Wayne Swan said that the government stood by its forecasts.
However Andrew Robb said that it was just a political fix to get through the election. He said that with the Greens backing the Gillard government would now widen the tax net to fill that gaping hole in their budget.
The almost $8 billion shortfall was being questioned by opposition treasury spokesman Joe Hockey, who said that the government needs to explain urgently just how it plans to make up the estimated shortfall.
Julia Gillard assured mining companies subject to the MRRT that the rate of the tax will not be increased. The treasury has not given any details about how the tax will meet budget forecasts.