Labor and the Greens say there's no need for Coalition to wait any longer to outline its election policy costings and explain how it would fund them.
This follows the release of the independent pre-election budget update.
But the Coalition says the update reveals new figures which need careful examination first.
Amanda Cavill
The Department of Treasury and Finance's Pre-Election Economic and Fiscal Outlook adheres to the forecasts for slower economic growth, rising unemployment and larger deficits over the next three years.
It says it expects the federal budget deficit to be just over $30-billion this financial year - unchanged from the government's own forecast.
But, the statement also says more asylum boat arrivals are expected this year despite Labor's tough new policies.
It predicts 15,600 people will arrive in 2013/14 - up from the May budget estimate of 13,200.
And the statement has predicted the revenue from the carbon tax will increase rather fall.
Joe Hockey says the revisions demonstrate that the government's budget forecasts are based on unreliable figures.
"We will carefully consider a lot of the detail in this document. The fact that the carbon tax has increased by nearly a quarter of a billion dollars in 11 days. This is an extraordinary revelation. And the fact that the Treasury and the Department of Finance have gone to significant lengths to try and quantify the risk scenarios associated with the failed border protection policy says everything about the inherent risks in the budget."
Mr Hockey says other risks revealed in the pre-election costings include the unresolved crisis in the eurozone, and anxiety in financial markets about the unwinding of US monetary policy.
He also says Treasury is concerned about the recovery in Japan and economic developments in China, and the effects these could have on the Australian budget.
Treasurer Chris Bowen says it's only prudent for Treasury to model its figures on a worst-case scenario.
He says the government is confident its new asylum seeker policy will stop boat arrivals.
He says it's time the Coalition released its costings.
"It does go to implications of alternative arrival scenarios. That's unsurprising that if arrivals increased further then costs would increase further. Yes that's right. But they are alternative scenarios. From this day forward there's no excuse for the opposition not to release all it's costings, how it intends to pay for its policies."
The Coalition has already referred about 200 policies to the Parliamentary Budget Office for costing.
At the previous federal election, the Labor Party released its election costings the day before polling day.
Mr Abbott says the Coalition won't leave it that late.
"The current government released its costing document at five o'clock on the Friday before the 2010 election. Now we'll do a lot, lot better than that. And we will be starting to announce some of our significant savings after we have had a thorough consideration of the PEFO document."
Mr Abbott is expected to release more detail in coming days on his $4.3 billion paid parental leave policy which would give mothers a full working salary for six months with a cap of $75,000.
Other policies that will be under scrutiny are the $5 billion tax cut for business and the costs of scrapping the carbon and mining taxes.
Greens Leader Christine Milne says her party has already released its costing and it's time the Coalition did the same.
"The Greens are saying we are taking into this election fully-costed policies.����� And I challenge Tony Abbott. You've run out of time. Please stop saying to the Australian people that you will tell them before the election where the money's going to come from because there's only a few weeks left. People want to know now how the Coalition intends to fund its policies."
Labor says it will be releasing its own costing in the next few weeks detailing how it will pay for its promises.
Treasury has estimated that there are $12 billion worth of government-announced tax policies that would require new legislation to come into effect.
These include increases to the tobacco excise, a crackdown on corporate tax loopholes, changes to the Fringe Benefits Tax reporting arrangement on cars, the deferral of personal income tax cuts, and bringing forward the Emissions Trading Scheme.
