Labor and the Coalition are embroiled in claim and counter-claim over election costings and budget savings.
Treasurer Wayne Swan says the coalition has an $800 million black hole in its budget savings because it has overestimated the savings from scrapping Labor's national broadband network (NBN).
But the opposition has countered by claiming the government has a $3.4 billion black hole caused by the fact it's spending much more than saving.
Mr Swan said today the Coalition couldn't save $2.44 billion over four years as planned by axing the NBN.
"There's certainly an $800 million hole in a budget saving that they are claiming when it comes to interest to the cost of the NBN," he told the Fairfax Radio Network.
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Mr Swan was referring to a Treasury analysis released to The Sydney Morning Herald on Tuesday. But the opposition says it hasn't seen the analysis.
Opposition treasury spokesman Joe Hockey attacked the newspaper for running the story without seeking a reaction from the coalition.
Asked if the story was correct, he told ABC Radio: "How do I know?" "I don't know what's in the document.
"This is a secret Treasury document ... that we have not seen."
Mr Swan used the analysis - coming just a day after Mr Hockey contradicted his leader Tony Abbott to the tune of $7 billion on the size of the coalition's spending promises - proved the opposition wasn't fit to manage the economy.
Opposition Leader Tony Abbott said he was sceptical about the Treasury analysis and was confident the coalition's own figures would "absolutely stack up".
"No one's seen this thing," he told Sydney's TripleM Radio.
"This is coming from the government which couldn't get its mining tax figures right."
Mr Abbott was referring to Treasury estimates for revenue from Labor's planned super profits tax on mining companies. Initially in May, it said $12 billion would be raised from the tax.
Two months later it revised that figure to more than $20 billion because of higher estimates for commodity prices.
Opposition finance spokesman Andrew Robb said it was not good enough for Labor projects to have been costed from the budget without providing the details.
"They haven't identified where it was in the budget, how it was in the budget," he told ABC Radio.
The coalition yesterday listed 211 of Labor's spending pledges, saying they amounted to $5.8 billion.
But Labor had only ever said it was spending about $2.9 billion, leaving a $3.4 billion hole, Mr Robb said.
