Prime Minister Tony Abbott has declared the Coalition Government will be "the best friend Medicare has ever had" after Health Minister Peter Dutton flagged an overhaul of the system.

Mr Dutton used a major speech yesterday to declare he wants there to be a frank, fearless and far-reaching discussion about the health system.

He is suggesting Australians who can afford it should pay more for their healthcare, and last night told the ABC's 7.30 program that there needs to be discussion around co-payments.

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There has recently been debate over a proposal to charge patients $6 to visit their general practitioner after a Commission of Audit, set up by Mr Abbott, received a submission recommending the co-payment system for GP visits.

But the Prime Minister would not be drawn on the idea of co-payments.

"As a health minister in a former government, I used to say that government was the best friend Medicare has ever had," he said.

"This leopard doesn't change his spots and I want this government, likewise, to be the best friend Medicare has ever had."

Opposition Leader Bill Shorten has vowed to fight any moves to dismantle Medicare.

"The Prime Minister promised before the election he wouldn't introduce any new taxes, but now he is trying to sneak in a new GP tax that will hit families every time they visit the doctor," he said in a statement.

Coalition plans for Medicare 'hard to work out'

Dr Jim Gillespie, from the Menzies Centre for Health Policy, says it is unclear what the Coalition's vision for modernising the Medicare system comprises.

"It's a little hard to work out because they promised almost nothing in the election campaign," he said.

"It was very hard to find out what they were planning and a lot of them merging by nudges and winks and little suggestions along the way, but a lot of it seems to be about a very old Liberal hostility towards the universal nature of Medicare."

Dr Gillespie says while there is significant waste in the system and changes to improve efficiency would be welcome, the system is not unsustainable.

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"I think a lot of the waste in the system comes because it's grown very slowly and with new benefits being added," he said.

"We now scrutinise new benefits as a committee that looks at both the clinical evidence for something going onto the Medical Benefits Schedule. So new services get looked at but most of the services went on and were never scrutinised.

"Those who work in that area have estimated that as much as a quarter of what we're paying for in Medicare, we just don't know whether it's working or it may not even be working at all."

Medicare system should 'focus on prevention'

One of the architects of the Medicare system, Stephen Duckett, says a co-payment is not the way to make the health system more economically sustainable.

"The co-payment is a pimple on a pumpkin," he told ABC News 24.

"It doesn't raise much money. It may not raise any money if people go to a hospital emergency department instead."

Dr Gillespie says if the co-payment scheme is introduced, patients will "end up in hospital with pneumonia when an antibiotic from a GP could have fixed up what was then just a sniffle".

Sorry, this video has expired Stephen Duckett speaks with ABC News Breakfast

Professor John Dwyer from the University of New South Wales agrees, saying the nation's health system needs to focus more on prevention to contain costs.

"We've got a terrible burden of chronic and complex disease in Australia [that are] largely lifestyle related," he said.

"Many countries are swinging their healthcare systems around to put the emphasis on prevention, not on sickness, and that's a very cost-effective strategy.

"Medicare needs the infrastructure to move us in that direction."

Labor's health spokeswoman Catherine King says it is becoming clear the Coalition is out to destroy Australia's universal healthcare system.

"Australians who can afford to pay more already do so through a greater contribution to the Medicare levy," she said in a statement.

"What Mr Dutton is really talking about is dismantling our fair and sustainable system in favour of a private health system [as] exists in the United States."