But Prime Minister Kevin Rudd denies the budget is based on overly optimistic economic assumptions, saying he's sure Treasury officials have done their homework.
Many businesses say bomming growth is not a given, especially considering the
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government's proposed 40 per cent tax slug on the mining industry.
But Mr Rudd said assumptions made about Australia's growth were conservative if anything.
"The treasury boffins analyse these things very carefully," he told the Seven Network on Wednesday.
"They've analysed carefully China's predominant growth potential, they've looked at where commodity prices go, not just for China, but remember we're talking about Japan, Korea and other countries as well.
"They always pitch a conservative view out.
If you look at where they're pitching commodity prices in the future, it's quite low against what the market analysts are saying."
But miners have continued their attacks since the 'Resources Super Tax'was announced following the Henry tax review
Queensland Resources Council chief executive Michael Roche says the tax wasn't necessary, and will actually hit government income.
"Without this super profits tax, there is an enormous contribution every year to the federal budget from resource sector taxes," he told the ABC.
