Abbott still wants 2017/18 balanced budget

Tony Abbott is determined to get his government's finances back into balance despite continued objections to some of its May budget measures and the additional costs of beefing up national security.

While the prime minister accepts there needs to be negotiation in the Senate to get some measures passed, he insists his government isn't walking away from any of the budget changes because of the debt and deficit "disaster" it inherited from Labor.

"Change is not an optional extra, change is an absolute necessity," Mr Abbott told reporters in Canberra on Wednesday.

"This government is absolutely determined to get us back to broad balance by 2017/18 as we outlined in the budget."

Treasurer Joe Hockey agrees that if the budget doesn't get back to surplus, Australia can't start paying down its debt.

"It means when the next downturn comes Australia is going to be in a far more vulnerable position," he told Fairfax radio.

He rejected as "wrong" a report that he's about to raise the white flag on $30 billion of budget savings being blocked in the Senate.

The budget is facing stiff opposition on a number of measures, such as indexation changes to the age pension, a $7 GP co-payment and deregulation of university fees.

Mr Hockey concedes he may be forced to look at "new ideas" if they don't get through, as well as looking for further savings to help pay for the $630 million in tougher counter-terrorism measures and the looming Iraq mission.

Details will be revealed in December when he publishes the mid-year budget review, although the treasurer has ruled out a special tax levy to pay for national security measures.

Opposition Leader Bill Shorten said the budget was in chaos and disarray because it is unfair.

"If you thought this budget was a shocker, you ain't seen nothing yet," he told reporters in Canberra.

He also warned against using Labor's support for the government on national security to justify its mismanagement of the budget.

"That would be a dreadful mistake by the government," he said.