THE Opposition Leader, Tony Abbott, has confirmed claims by his colleagues that the big miners are saying in private they do not expect to pay much mining tax, if any at all.

Following similar public claims last week by the shadow treasurer, Joe Hockey, and the Opposition's resources spokesman, Ian Macfarlane, Mr Abbott said yesterday the mining tax would raise nowhere near the revenue needed to fund all its associated measures and would leave a black hole in the budget.

"The more we learn of the mining tax, the less likely it seems that those revenue forecasts are correct" ... Tony Abbott. Credit:Penny Bradfield

''The more we learn of the mining tax, the less likely it seems that those revenue forecasts are correct,'' Mr Abbott told Sky News yesterday. ''If you actually talk to the miners, none of them expect to be paying any serious amount of mining tax.''

The Minerals Resources Rent Tax was negotiated in 2010 between the government and the three minerals giants, BHP Billiton, Rio Tinto and Xstrata.