Opposition Leader Bill Shorten will unveil a major plank of Labor's pitch for middle Australia on Thursday, pledging to re-invigorate Medicare by restoring the inflation-based growth rate to Medicare payments to doctors for the provision of medical services.

The move, which builds on one of Labor's traditional strengths of healthcare, is designed to outflank the Coalition and reassert Labor's claim of being the best party to deliver on basic services for ordinary households.

Its timing may also be fortuitous, as it comes as medical professional bodies grow increasingly frustrated at what they believe is a chronic funding shortage in Medicare, which is undermining the very system of universal health insurance.

With concerns over healthcare forming such a key part of the election contest, Fairfax Media understands the Royal Australian College of General Practitioners is preparing to embark on an "unprecedented" $1 million television, radio, and digital media campaign aimed squarely at pressing the major paries into properly funding Medicare.

The campaign, set to begin from May 29, warns Australians that voting for a continuation of the freeze is a vote for higher GP costs.

"The federal government's freeze on Medicare rebates means you'll pay more to see your doctor," it states before concluding with the warning: "It's just not right. In Australia your wealth shouldn't affect your health. Say no to the freeze on Medicare rebates."

Doctors warn the system is approaching a point of collapse as patients put off visits to the doctor to avoid higher costs - creating worsening medical conditions - or elect to use public hospital emergency rooms, clogging up already over-crowded system and also shifting costs on to the states.

Labor's plan to restore indexation is expected to cost $2.4 billion over the first four years from its intended commencement date of January 1, 2017, making it the biggest spending commitment from either side of politics since the formal election campaign started.

It says the extra funding commitment will be met by not proceeding with the Coalition's 5 cents company tax cut over the next decade, and by not proceeding with either the Vocational Education and Training loans scheme, and the Coalition's new baby bonus.

The plan would end a two-year freeze on the Medicare Benefits Schedule, which took GPs and other health professionals by surprise in the recent budget.

Mr Shorten will argue the move will rescue Medicare from progressively slipping behind in the reimbursement of GP costs as health inflation widens the gap between the rebate and the cost of providing the service, resulting in fewer GPs bulk-billing and more electing to charge over and above the scheduled fee.

"Nobody wants to head down the same path as America when it comes to our health system," Mr Shorten said, advising that the restoration of indexation would apply to services from GPs, allied health practitioners and from medical specialists.

"We will reverse Mr Turnbull's cuts, which will reduce bulk-billing and hit Australian families every time they visit the doctor."

The proposal is likely to win the support of doctors' groups such as the Australian Medical Association, which had complained that the surprise two-year extension of the scheduled fee freeze was becoming a co-payment by stealth as GPs and other health providers were forced to charge more and more over the schedule to stay afloat.

"Having failed three times to introduce its GP Tax – due to Labor's opposition in the Senate – the Liberals imposed a GP Tax by stealth, freezing the indexation of the rebates paid to doctors for four years," Mr Shorten said.

"Then in his first budget, Malcolm Turnbull ripped another $925 million out of Medicare by extending the freeze by a further two years to 2020."

The Parliamentary Budget Office has costed the proposal and predicts a four-year price tag of $2.4 billion with $1.1 billion of that falling in the fourth year. Over a decade, the cost of indexation would be $12.2 billion, according to the PBO modelling.

In recent weeks, both the AMA and the RACGP have warned of doctors abandoning bulk-billing completely after being required to absorb rising costs without passing those on to their patients.

The RACGP campaign, which will run nationally and via local media in key marginal regional electorates in New South Wales, Queensland and Tasmania, represents a serious attempt by the College to assert a stronger role in public health policy, and in the protection of its approximately 33,000 members.

Both parties have used freezes on indexation in the past to help balance the federal health budget.

Labor froze indexation for eight months in 2013, lifting it briefly for GPs in 2014-15. The Coalition extended it for four years in 2014, and this year extended it a further two years to 2020, to save $925.3 million.

Follow us on Twitter