OPPOSITION Leader Tony Abbott insists the government is "crab-walking away" from its promised budget surplus and has warned it could threaten future funding for a National Disability Insurance Scheme (NDIS).
Mr Abbott on Tuesday said the coalition "enthusiastically supports" current government commitments for the NDIS, such as trial sites.
But the scheme needed the funding certainty provided by getting the budget back to a strong surplus as soon as possible.
"I regret to say that this is highly unlikely, indeed becoming increasingly impossible, under the current government," Mr Abbott told reporters in Canberra.
"The current government is crab-walking away from the promised surplus."
Mr Abbott again pursued Prime Minister Julia Gillard during parliamentary question time, asking if she could guarantee a surplus in 2012/13, given such promises had been made in the past.
Ms Gillard again referred Mr Abbott to the government's mid-year economic and fiscal outlook (MYEFO) released last week.
"In it we have delivered billions of dollars in savings ... to return the budget to surplus and we are on track to deliver it," she told parliament.
Ms Gillard questioned whether the opposition would support those savings measures, adding Mr Abbott couldn't be taken seriously when the opposition refused to allow its policies to be "properly" costed.
Shadow treasurer Joe Hockey continued the budget theme, asking Treasurer Wayne Swan whether he stood by a previous statement he would deliver a surplus "come hell or high water".
"We are bringing our budget back to surplus, and we stand absolutely by all of the forecasts that were contained in the mid-year budget update," Mr Swan replied.
"We could not be clearer than that."
Mr Swan said it was important to come back to surplus to give the Reserve Bank maximum flexibility when it comes to cutting interest rates, should they decide to do so.
The opposition appeared to be posing some sort of hypothetical "what-if scenario", he said.
"The fact is this, what if something happens in the global economy?" Mr Swan said.
"I say to them this, we have a proven track record of responding to the volatility in the global economy, and when our country was threatened, we saved it."
But opposition immigration spokesman Scott Morrison maintained the rising volume of asylum seeker boat arrivals would hinder the government's ability to deliver a surplus.
He said as many as 40 boats had arrived in Australian waters in October and arrival numbers were four times what the government had anticipated in the May budget.
"With the boats continuing to arrive, at the rate that they are, this will continue to crash this government's surplus," he said.
The opposition also pointed to the zero revenue from the government's minerals resource rent tax (MRRT) in the first quarter of its introduction.
But Trade Minister Craig Emerson said the opposition was indulging in "the ultimate in short-termism". The budget update forecast $2 billion in MRRT revenue for this financial year.
A Newspoll published in The Australian on Tuesday showed only one in four voters believe Labor will deliver a surplus.
