Australian workers could be locked out of home ownership unless property concessions are reined in, but any reform would require careful manoeuvring from the government.
As the federal government seeks ways to reinvigorate the nation's languishing productivity, the Australian Council of Trade Unions has urged it to reform the tax system and make housing affordable.
Tax concessions like negative gearing, which allows investors to claim deductions on losses, and the capital gains tax discount, which halves the amount of tax paid by those who sell assets owned for a year or more, have incentivised property investment and tied up capital that could otherwise be invested more productively, according to the union.
"Working people can no longer afford to live near where they work and young people are locked out of the housing market and locked into high rents," ACTU secretary Sally McManus said.
"It's just not right and has to change."
The union has proposed limiting negative gearing and capital gains tax discounts to a single investment property, though those tax breaks would be grandfathered for five years on properties that already benefit, giving investors time to adjust.
Independent economist Saul Eslake, who has spent decades advocating for the abolition of negative gearing and the capital gains discount, said the ACTU's proposal was "good policy".
"One of the things about our tax system is it provides enormous incentives for people to invest in residential property - not so much in building more of it but in speculating that its price will go up," he told AAP.
But reforms to property tax concessions have historically been political kryptonite for Labor.
A previous proposal to limit negative gearing contributed to the party's narrow defeat at the 2019 election, which may not come as a surprise given about one in five taxpayers have at least one investment property and about half of them are negatively geared, Australian Taxation Office statistics have found.
While Labor won the May election in a landslide victory, Australian political orthodoxy would suggest the government may not do much with its margin and instead seek to argue for an expansive mandate at the 2028 contest when it will be prepared to take some flack.
"There's a lot of votes at risk," Mr Eslake said.
"But what's the point of having political capital, if you're not prepared to spend it?"
Treasurer Jim Chalmers appears keen to break from the political orthodoxy in pursuit of major tax reforms.
However, this will come at a cost, Mr Eslake said.
Australia's last big tax reform - the introduction of the GST - came during a time when the Howard government had maintained a significant surplus that could be drawn down on to ensure everyone was better off.
The current government is staring down a decade of deficit, which means some people will have to be worse off.
(But) the government can afford to alienate people who would never vote for it in the first place," Mr Eslake said.
He says this is the implicit attitude behind such Labor policies as its proposal to lift taxes on super balances above $3 million from 15 per cent to 30 per cent, which will impact about 0.5 per cent of savers.
Dr Chalmers will convene a roundtable later in August that will focus on lifting living standards by improving productivity, building resilience and strengthening the budget.
The union has also urged the government to implement a minimum 25 per cent tax rate for individuals who earn more than $1 million and a cap on the Fuel Tax Credit Scheme for big business to ensure companies cannot claim more than $20 million in those credits.
But the Business Council of Australia has hit back, calling the proposals "ad hoc tax grabs".
"You don't fix Australia's lagging productivity and investment by taxing businesses more and making Australia less competitive," chief executive Bran Black said.