The aim of GP co-payments might ostensibly be to reduce the mounting cost of health care, but the real intention is to take a hammer to public health, writes Mungo MacCallum.

The trouble with the Liberals is that they just can't keep their hands off it - Medicare, that is.

While in opposition, in the lead-up to the election, Tony Abbott insisted that Medicare was sacrosanct; why, the Liberals were the best friends Medicare had ever had. But as soon as his feet touched the ground as Prime Minister, Medicare was promptly unfriended.

While there were no-go areas for his hand picked Commission of Audit (his personal cornucopia, the Paid Parental Leave Scheme, being the most obvious), Abbott was happy to put Medicare on the operating table, a suitable subject for surgery. And already the pre-op sedation is well under way.

Terry Barnes, who worked for Abbott during the PM's spell as Health Minister, popped up with the suggestion that a good starting point might be to go back to the twice-rejected concept of a co-payment by patients for all appointments with their GPs - say about $6 a visit. Byrne's proposal came as part of a paper prepared sometime in 2013 for the Australian Centre for Health Research, a think tank funded by and for the private health funds and private hospitals - the natural enemies of Medicare. As soon as the Commission of Audit was set up, the ACHR passed it up the line.

Barnes professes to be surprised that this fortunate piece of timing has raised the suspicions of the defenders of Medicare; but if he is serious he is being extraordinarily naïve. The private health industry, through the Liberal Party, has a long history of trying to undo Medicare and its predecessor, Medibank, by stealth. Indeed, its opposition to public health dates back to the 1920s when the wealthy surgeon Earle Page - later to become federal health minister in the government of Robert Menzies - used to inveigh against the public hospital system, which, he claimed, was in unfair competition to the private hospitals - of which he himself owned several.

These days the attack has to be a little more subtle: Labor's pride and joy is too popular to tackle head on, but over time it can be brought to its knees, and it has been before. Gough Whitlam's original proposals for Medibank were ferociously resisted by the coalition of the day, which voted against them at every opportunity and egged on the more rabid elements of the medical profession, who saw it rather confusingly as both socialised medicine and a totalitarian measure designed to destroy the people's health. The responsible minister, Bill Hayden, was portrayed by the General Practitioner's Society of Australia as a uniformed Nazi.

Eventually the scheme was passed in a joint sitting of parliament following the double dissolution election of 1974, but the Whitlam government was out of office before it could be securely bedded down. His successor, Malcolm Fraser, promised faithfully to retain Medibank but spent the next eight years white-anting it to the extent that when Bob Hawke came to power in 1983 he virtually had to start again.

This time the re-named Medicare had 13 years to settle. In the process it became one of the country's most revered institutions, but to the Liberals it was still anathema; public health was supposed to be a safety net to catch those who could not afford the real thing, not the default position. The John Howard years saw the private sector encouraged, cosseted and subsidised in the hope that eventually Medicare would just wither away, but in the end it outlasted its opponents - though not without sustaining injury; the bulk billing of patients, which was supposed to be the norm, increasingly became an exception, a gesture of charity meted out to the old and indigent.

But it remained too prevalent for the real free-marketeers, who have enthusiastically embraced Byrne's idea of a $6 co-payment. It might look like a token, the price, as they joke, of a cup of coffee or a glass of beer - free marketeers drink in expensive bars these days. But in practice it would be the thin edge of the wedge; the decisive step in the demise of the ideal of universal, tax-payer funded, health care.

The economic, as opposed to the ideological, aim of the co-payment is allegedly to reduce the mounting cost of health care driven by an ageing population and increasingly expensive technology: by putting a concrete price signal on obtaining medical advice, so-called "unnecessary" visits to the doctor would be discouraged. "Unnecessary," incidentally, is not an adjective the rich use to describe their own consumption of scarce medical resources through elective and cosmetic surgery. But the poor, it is assumed, misuse their GP, adding to public expense in ways the rich do not.

The theory is that if they or their families are genuinely sick, they will be prepared to make the financial sacrifice the co-payment demands, or, if they don't, the emergency system of the public hospitals will pick up the pieces. At first the actual budgetary gains would be minimal - barely covering the costs of administering the new system. But over time the co-payment could unobtrusively grow bigger, and bigger, until Medicare as we know and love it would cease to exist.

Of course there is a better, fairer, way: simply increase the existing Medicare levy on taxable income. Double it if necessary. That way the progressive tax system would ensure that the extra cost burden would be shared equitably between rich and poor. And the political pain would be easily containable: experience has shown that Australians are quite willing to pay for a world's best practice health system when the facts are clearly and honestly put before them. But to go down this path would be to endorse and preserve the public health system, and this, to use a favourite phrase of Tony Abbott's, is not something that is in the Liberal DNA: never has been, never will be.

Mungo MacCallum is a political journalist and commentator. View his full profile here.