The Mid Year Economic and Fiscal Outlook (MYEFO), to be officially announced on Dec 17, is expected to confirm Australia's budget deficit of $50 billion.

Before the September election, the Labor government had predicted a budget deficit of $30 billion. Prime Minister Tony Abbott, on the other hand, vetoed to decrease or reimburse the deficit within his first term. However, he is singing a different tune at present, saying he can return the deficit come his second term and had yet to confirm the exact date.

The federal government said that the biggest contributing factor to this $50 billion budget deficit was an over expenditure in offshore processing.

On Friday, Dec 13, Immigration Minister Scott Morrison announced that the government has to allot an extra $1.2 billion on offshore processing, saying that the Labor government had failed to apportion budget to cover spending on Nauru and Manus Island.

"This government is now more than doubling the capacity on Nauru and Manus Island and we expect to have that completed within the next month. If you are going to run offshore processing you need to ensure that everybody is subject to it, with no exceptions, and that's just simply not what the previous government funded. This government has corrected that," Mr Morrison said.

Speaking with ABC, Mr Abbott said that the MYEFO to be announced Tuesday is a reflection of Labor's wastefulness.

"What I think we will see in MYEFO is the full extent of Labor's profligacy,The MYEFO figure tomorrow will be Labor's last budget statements and Labor's only truthful budget statement, because what is in MYEFO tomorrow will be a result of the decisions which the Labor Party has taken. But the job of the MYEFO statement, is if you like, to rule a line under Labor's era of debt and deficit , so that henceforth from this time on, the Government can begin the fiscal repair job that our country needs," Mr Abbott said.

Meanwhile, Opposition treasury spokesman Chris Bowen is putting the blame to the current government.

"Mr Hockey denied in Parliament last week that the impact of his decisions would top $9 billion this financial year. We'll see if he was telling the truth when he said that when the MYEFO is released," Mr Bowen said.