Labor has launched a last-ditch attack on Prime Minister Malcolm Turnbull’s trustworthiness by casting doubt on his pledge to “never ever” privatise Medicare.

With prime time TV ads featuring former Labor PM Bob Hawke warning of a Liberal agenda to privatise Australia’s universal health insurance system, Opposition Leader Bill Shorten is trying to elevate trust to a government-changing issue.

“Piece by piece, brick by brick the Liberals have never liked Medicare and they want to tear it down,” Mr Shorten said at Labor’s formal campaign launch at Dame Joan Sutherland Theatre in Parramatta on Sunday.

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There has been a consensus among political observers, backed by marginal seat polling, that Mr Shorten will fall short of the 21 seats needed to form government.

The ‘protect Medicare’ wedge appears designed to motivate still undecided marginal seat voters to cross to Labor. It could be unfair. It could be untrue. But that’s adversarial politics.

When the Hawke TV ads first appeared last week, an outraged Mr Turnbull called them a Labor scare campaign. In the ad, Mr Hawke says the Liberals would not have set up a Medicare privatisation taskforce unless the ultimate aim was to privatise.

Labor has recruited former PM Bob Hawke to drive home its Medicare warning.

Labor is now expected to festoon polling booths on July 2 with big banners warning about the ‘threat’ to Medicare. Other Labor ads on trust are expected to include John Howard’s “never ever” promise not to introduce a GST and Tony Abbott’s more recent 2013 election eve promise that there would be “no cuts to health or education”.

Mr Turnbull complained on Sunday that Mr Shorten is “peddling an extraordinary lie, so audacious it defies belief”.

New proof?

At Labor‘s campaign launch, Mr Shorten said he had “new proof” of Mr Turnbull’s agenda.

“The Liberals have given the Productivity Commission new riding instructions, to investigate privatising human services and Americanising Medicare,” he said.

The Productivity Commission has been tasked by Treasurer Scott Morrison to review all aspects of human services delivered by government, including community services, social housing, prisons, disability services and Medicare.

The terms of reference include examining “private sector providers and overseas examples like the United States” for alternative service delivery models.

The review is reported to be considering efficiency reforms to the Medicare payments system.

Mr Turnbull refuted the claims on Sunday.

Prime Minister Turnbull says Labor’s Medicare campaign is a lie. Photo: AAP

“It will never, ever be sold,” he told reporters in Sydney. “Every element of Medicare services that is being delivered by government today, will be delivered by government in the future. Full stop.”

‘You ain’t seen anything yet’

At the launch, Mr Shorten promised a range of last-ditch spending commitments to try to rebuild Labor’s campaign momentum beyond what he called an “honourable defeat”.

He announced $20,000 tax breaks for small business if they employed parents returning to work, carers, people under 25 or over 55. This targeted incentive would create 30,000 jobs a year, Mr Shorten claimed. He announced capital city public transport investments, $81 million for suicide prevention and to reverse Turnbull government cuts to diagnostic imaging and pathology.

Mr Shorten repeated Labor’s commitment to Gonski needs-based school funding, but significantly there was no commitment to the full future funding of Gonski once agreed by the states and the Gillard government (WA excepted).

Quentin Dempster is a Walkley Award-winning journalist, author and broadcaster with decades of experience. He is a veteran of the ABC newsroom and has worked with a number of print titles including the Sydney Morning Herald. He was awarded an Order of Australia in 1992 for services to journalism.