Federal Health Minister Peter Dutton has been accused of softening up voters for the introduction of a GP co-payment after saying Medicare is unsustainable and those who can afford it might need to pay more.

Mr Dutton wants a national conversation on rising healthcare costs and says the government is considering ways to reign in spending as part of its commission of audit to cut expenditure across the federal budget.

He says the Abbott government’s Commission of Audit will help overhaul the country’s “unsustainable” health system.

Co-payments of up to $6 to visit the doctor have been flagged as one way to tackle the healthcare burden, sparking concerns the Abbott government will target the Medicare system in the May budget.

Asked if he backed a co-payment, Mr Dutton pointed out many Australians already made a co-contribution when it came to prescription medicines and private health cover, while others were already paying to see a GP.

“I want to make sure that, for argument’s sake, we have a discussion about (people) on reasonable incomes whether we should expect to pay nothing when we go to see the doctor,” he told the ABC TV on Wednesday night.

“Should we expect to pay nothing as a co-contribution, and other taxpayers to pick up that bill?”

We don’t want to create a situation where people defer seeking healthcare.

In comments that suggest people over 65 years may be targeted by the government, the minister said co-payments should be considered “regardless of people’s age”.

“If they have a means to contribute to their own health care, we should be embarking on a discussion about how that payment model will work”, Mr Dutton said.

Labor’s health spokeswoman Catherine King warned Mr Dutton intended to “dismantle” Medicare by introducing a “GP tax”.

“The introduction of a GP tax will reduce access to doctors for all Australians,” she said on Thursday in a statement.

The Australian Medical Association is concerned a co-payment would deter people from seeing their GP.

“We don’t want to create a situation where people defer seeking healthcare, and that might be expensive later,” president Steve Hambleton told ABC Radio.

The Prime Minister speaks out

Mr Abbott has downplayed concerns his government may introduce GP co-payments, saying he won’t change his spots when it comes to being the best friend of Medicare.

He acknowledged the country’s finances were under pressure and it was “very important that we do what we can to fix the budget as quickly as we can”.

However, Mr Abbott said any savings measures had to be consistent with the coalition’s pre-election commitments.

“Don’t forget, I said we were going to be a no-surprises, no excuses government,” he told reporters in Sydney.

Mr Abbott pointed to his remark when he was health minister that the then Howard government was the best friend Medicare ever had.

“This leopard doesn’t change his spots,” he said.

“I want this government to be likewise the best friend that Medicare has ever had.”

Despite the prime minister previously stating “nothing is being considered, nothing has been proposed, nothing is planned” on GP co-payments, Mr Dutton said a national conversation was needed on how to pay for rising health costs.