The coalition's costings are full of holes and dodgy maths, Treasurer Chris Bowen says.
Mr Bowen says the coalition's numbers - finally revealed on Thursday - are wrong in a number of ways.
For example, the coalition announced funding for a road in Perth this week but it's not included in the figures, the treasurer says.
"They've got holes all over the place," he told ABC radio on Friday. "This is a squib of a document, this is dodgy maths."
Mr Bowen says it is clear why the coalition decided to release the numbers so close to election day.
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"Why do it in the last 48 hours if you're not afraid of scrutiny? They are trying to hide things."
Mr Bowen criticised the coalition for walking away from what was a bipartisan commitment to rapidly increase foreign aid spending to 0.5 per cent of gross national income.
While Labor had delayed the target by a couple of years, it remained committed to it, Mr Bowen said.
"They've just said 'We'll get there one day', but they've not even put a date on it."
Opposition Leader Tony Abbott on Friday clarified his plans for a commission of audit, which will be charged with examining where taxpayer dollars are spent if the coalition wins government.
He said its job was not to determine whether coalition policies were a good idea.
"It's not to review programs, it's to review administration," he told Melbourne's 3AW Radio.
"So the audit commission is not going to go in there and say, `oh, you know, we think paid parental leave is a bad idea'.
"The audit commission is to go through the administration of government and say `well, this is what you're doing, maybe it can be done better this way rather than that way'.
"It's about making the programs that the government has run efficiently and as effectively as they can."
