Australia will return to a budget surplus by 2013 as driven by a determined and committed Labor-led federal government.

This insisted by Finance Minister Penny Wong despite admission made by Treasurer Wayne Swan on Thursday that the solid upward surge of the Australian dollar would chip away considerable chunk of the government's revenue on mining tax.

Also, opposition treasury spokesman Joe Hockey countered Senator Wong's projection as he argued that the climbing Aussie currency, which already reached parity with the US dollar, would definitely take away some government revenues.

Mr Hockey added that this would be compounded by the federal government's unwillingness to cut down on expenditures, which only pointed to the impending reality that a budget surplus would be out of the question for the next two years.

Mr Swan conceded that the original forecast of up to $10.5 billion in revenue from the mineral resources rent tax would be hard to meet due largely to the high cost of Australian exports as he reminded that the forecast was made when the Aussie dollar was just 85 cents against the US dollar.

While remaining committed to the target budget surplus, Senator Wong agreed with the assertion that the strong performance of the Australian currency would negate the projected gains on government revenues.

Such pronouncements from the two Labor stalwarts, according to Mr Hockey, only confirmed the Coalition fears that a surplus would not be delivered as he challenged the wisdom of implementing a tax measure that would eventually fail to return a previously determined profit.

He could only wish that that federal government would listen to suggestions by the Coalition to cut down on expenses, which maybe the necessary step to start the return at least to a balance budget if a surplus proved to be elusive in the near term.

However, Senator Wong downplayed suggestions that the government is gravitating towards overspending, stressing that strict rules were being followed "to limit the growth in real expenditure that does require us to take a much disciplined approach to spending."