Federal Treasurer Chris Bowen insists his budget update will show a pathway back to surplus in 2016/17, in line with the last fiscal forecasts.
Mr Bowen and Finance Minister Penny Wong are working on an economic statement to be delivered before the federal election.
"We will stick to our budget strategy. We will offset new expenses and we will issue an economic statement in an open, clear and transparent way," he told reporters in Sydney on Friday.
Asked if he had been left a "lemon" of a budget by his predecessor Wayne Swan, Mr Bowen said: "No".
But he says the budget has been impacted by a further fall in the terms of trade.
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The treasurer lashed out comments from opposition counterpart Joe Hockey, accusing him of "crabwalking" away from a commitment to release his policy costings based on the departments of treasury and finance's independent pre-election economic and fiscal outlook (PEFO).
"They are walking away from the Charter of Budget Honesty which was established by their own (former treasurer) Peter Costello," Mr Bowen said.
Mr Hockey has cast doubts on the independence of PEFO, which will be handed down by the departments within 10 days of the writs being delivered to dissolve parliament ahead of the election, saying he couldn't rely on Treasury's figures.
"Quite clearly by flagging an economic statement the government is trying to bully the public service into a set of the numbers that clearly do not properly represent the state of the budget," Mr Hockey told ABC radio.
Mr Bowen said he was "sick and tired" of the opposition trashing the reputation of Australia's public servants.
But Opposition Leader Tony Abbott said Labor's numbers could never be trusted.
"There is a crisis in cabinet over economic policy," Mr Abbott told reporters in Launceston.
"Right now there is apparently a split in the cabinet over the fundamental direction of economic policy. Quite likely the election will be put off even further because this government cannot get its economic policy right."
He says a coalition government will return to surplus as quickly as possible, but at this stage doesn't know the budget situation it will inherit.
Mr Hockey said they had used the Parliamentary Budget Office, state government colleagues and independent advisers to work out their policy costings.
"What I can say emphatically is that our numbers will be more reliable than anything the government publishes," he said.
Mr Bowen points out the opposition used an accounting firm during the 2010 election which was later fined for breaching professional standards because of the "sloppy" work it did.
"We are seeing yet again the same sloppy approach from the opposition," he said.
The trading of insults over the budget came the day after shadow finance minister Andrew Robb questioned the relevance of Australia's triple-A credit rating.
Mr Bowen said Mr Robb was "soon slapped down" by the shadow treasurer.
"This underlines the fact that the opposition isn't really up to the job of managing the Australian economy," Mr Bowen said.
