Greens Senator Dr Richard Di Natale. Photo: James Boddington
Senators plan to question the Abbott government's commissioners of audit on slaughtering the political ''sacred cows'' of the private health insurance rebate and negative gearing tax concessions.
The commissioners, including Business Council of Australia president Tony Shepherd and former Howard government minister Amanda Vanstone, are expected to appear on Wednesday before a Senate committee specifically convened to shine light on the audit process.
The commissioners have been given open-ended terms of reference to produce a road map for the Coalition's aim to return the budget to a continuing surplus equivalent to 1 per cent of gross domestic product.
The chairman of the select committee, Greens senator Richard Di Natale, said the commissioners had been charged with making recommendations about cuts to essential services, the privatisation of public assets, and major tax changes, but their deliberations were ''shrouded in secrecy''.
''To me, it's unthinkable that a group that's been charged with making such wide and far-reaching recommendations would do so in private, without any transparency,'' Senator Di Natale said.
He said in contrast to the conduct of other major inquiries, the commission had not published the submissions it had received, had not held public hearings, and it was not clear whether its reports - the first of which is due by the end of the month - would be made public.
Among the submissions that have become public is a proposal by Terry Barnes, a former adviser to Tony Abbott as health minister, for a $6 fee to visit the doctor.
Senator Di Natale said he was concerned that some savings options, such as negative gearing and the private health insurance rebate - which cost $5.5 billion in 2012-13 - were being spared from consideration for ''ideological reasons''.
''This is a case where the government's ideology is trumping not just fairness but efficiency in the health system,'' Senator Di Natale said.
''You would need to be an economic Luddite to continue with the current policy of subsidising the private health insurance sector while putting in a co-payment to see a GP.''
A recent analysis by the Grattan Institute found abolishing the rebate could save the budget $3 billion a year, even after taking into account the extra demands on the public hospital system that such a change would produce.
Such a saving would dwarf the $750 million over four years that Mr Barnes projected the $6 co-payment would save through reducing ''avoidable'' demands for GP services.
In a paper published last July, Terence Cheng, a research fellow at the University of Melbourne's Institute of Applied Economic and Social Research, argued that private health insurance rebates were ''fiscally unsustainable'' and did little to shift costs from the public to the private sector because public hospitals were responsible for caring for the most complex and expensive cases and people with private cover continued to use the public system.
But Mr Abbott has described the private health insurance rebate as ''an article of faith'' for the Coalition and has promised to repeal the rebate means test, which was introduced by Labor in 2012, within a decade.
Health Minister Peter Dutton said on Friday: ''The government is absolutely committed to increasing the rates of coverage of insurance in whatever way we can, and we will not abolish the rebate.''