A major global economic organisation has urged Australia to look for other ways to raise revenue rather than let a shrinking pool of workers shoulder the growing tax burden.
The Organisation for Economic Co-operation and Development says broadening the goods and services tax - and potentially lifting the rate - would help rebalance the tax system so retirees take on more of a share alongside workers.
Australia gets 26.5 per cent of its total tax take from GST, compared to the 32 per cent OECD average, although upping the rate comes with its challenges as all states and territories need to unanimously agree to any change.
It can also be a regressive tax and hit lower-income households harder, so the OECD recommended pairing it with bolstered social welfare benefits or other kinds of compensation.
In its economic survey report for Australia, the OECD also urged the federal government to revisit tax concessions on superannuation.
The government has already committed to halving tax breaks for those with super balances of $3 million or more, although capping pre-tax contributions or taxing earnings on the retirement phase were touted as some further options for reform.
The government's intergenerational report, released in August, pointed to an ageing population expected to put pressure on the nation's finances due to more spending on aged care and health.
The OECD said relying on personal income tax was risky under these demographic shifts as there would be fewer workers to tax and more demands on the public purse.
There are also savings to be found on the spending side.
"Encouraging more patient care in primary care settings and preventive health policies can reduce public spending growth as the population ages," the report said.
Mounting pressures on the budget and the need to find ways to pay for them were highlighted in a speech by former Department of Finance head Michael Keating at the Australia Institute's Revenue Summit.
Dr Keating said increasing taxes was politically challenging and would need popular support.
"Fundamentally, we need to improve the link in the public mind between its demand for services and the taxes necessary to pay for them," he said on Friday.
The federal government has been upfront about the spending challenges on the budget and has tried to claw back some extra revenue from large super balances, offshore gas companies and multinationals evading tax.
Assistant Treasury Minister Andrew Leigh said multinational tax dodging had been going on for decades and at a "colossal scale".
"For too long the global tax haven industry has gotten away with ripping off the citizens of other countries," Dr Leigh said at the conference.
Federal independent politicians Monique Ryan and David Pocock said the government could be extracting more revenue out of Australia's own fossil fuel resources.
Dr Ryan said Labor's efforts to reform the petroleum resources rent tax to make oil and gas companies pay more tax had been "incredibly disappointing".
"The increase in the petroleum rental tax is $500 million a year, which is absolutely nothing," she said.
