Federal Treasurer Wayne Swan said on Wednesday that Australia could expect a budget surplus of more than $2 billion by 2012/13, hailing the latest economic figures as indicators of the country's return to the black status and way ahead from any given major economy across the globe.

The federal government released its economic forecasts amidst frenzied preparation for a national election and on the forefront of the data were the apparent concessions that Prime Minister Julia Gillard had to make on the proposed mining tax, which allegedly cost the government up to $7.5 billion of projected tax collection.

The government figures showed that the federal budget would swing back to a $3 billion surplus in three years time, an amount three times larger than projected in May's budget.

It also showed that budget deficit would reach anew the $40 billion mark though it would be lessened considerably in 2011-12 at $10 billion while jobless rate was left untouched from the May budget, notching five percent for 2010-11 and 4.75 percent for 2011-12.

The government veered slightly away from the May budget on its growth forecast, predicting only of 3.75 percent for 2011-12 and three percent for 2012-13.

The Gillard government also underscored that the revised mining tax, its headline rate now reduced to 30 percent from the original 40 percent, would actually lead to a lesser loss revenue of $1.5 billion, which is a far cry from the $12 billion earlier projected when the proposed resource super profits tax was morphed into minerals resource rent tax.

The opposition, however, questioned the veracity of the figures furnished by the government and urged the prime minister to explain in details on how the numbers were arrived at though the documents have shown that official calculations were made in consideration of upwardly revised commodity prices.

The government said that the adjusted commodity price "forecasts increase revenue from the resource tax arrangements by $6 billion over the forward estimates," while it reaffirmed at the same time that the revised figures also pointed to a collection of $10.5 billion once MRRT is implemented.

On his part, opposition leader Tony Abbot called on the government to ensure that the extra windfall announced by Mr Swan today would be utilised to debt repayments and not to be rechanneled for 'pork barrel' use during the election campaign.