ALP supported co-payments in past: Dutton

Federal health minister Peter Dutton has pointed to Labor inconsistency on the proposed Medicare co-payment, saying it had supported previous measures for medicines and private health insurance.

Labor, the Australian Greens and Palmer United Party have declared they will oppose a $7 co-payment on visits to the doctor arguing it will hit the most vulnerable Australians.

But in his post-budget health briefing on Thursday, Mr Dutton said the government was simply asking Australians to make a modest and fair contribution to healthcare costs.

He argued Labor previously had backed co-payments through the Pharmaceutical Benefits Scheme, for private health insurance and specialists consultation.

"They should support these changes," he told an audience at Parliament House in Canberra of the government's budget measures.

Prime Minister Tony Abbott has said he is open to "horse-trading" to get his government's first budget through the Senate.

However, Labor's health spokeswoman Catherine King dispelled any thoughts the opposition may negotiate on the co-payment.

"We will not horse-trade ever on an issue that means that patients, the most vulnerable Australians, will be forced to pay more for their healthcare," she told ABC Radio.