Treasurer Jim Chalmers has ruled out changes to negative gearing and capital gains, while leaving the door open to the taxation of trusts.
Property investors are under the spotlight as the tax reform debate shifts to wealthier Australians.
Both Prime Minister Anthony Albanese and Opposition Leader Peter Dutton face pressure to revisit tax breaks on investment properties.
The Greens are proposing limiting negative gearing rules to a single investment property.
But Dr Chalmers says any changes are off the table.
"That's not something that we're proposing, not something that we are considering, not something that we are working up," he told Sky News on Sunday.
Asked if he had ever sought advice on changes to the taxing of trusts, Dr Chalmers said he had discussed all aspects of the system with the treasury department.
Negative gearing allows investors to claim deductions on losses, while the capital gains tax discount halves the amount of excise paid by people who sell assets that have been owned for 12 months or more.
Shadow treasurer Angus Taylor says the coalition won't support changes to negative gearing.
Asked if the coalition would consider making changes to capital gains and trusts, Mr Taylor said the coalition wasn't proposing "to go down those paths".
Independent MP Allegra Spender said the tax system as a whole needed to be considered.
"What I think we should be more broadly looking at is reducing ... the burden on workers from our tax system," she told Sky News.
"We need to get all those different settings right, and try and do a package that still means we can pay for the services that we care about."
Dr Chalmers agreed anyone earning $160,000 a year was in "middle Australia".
"I think of middle Australia as the people who get up and work hard to provide for their loved ones and get ahead," he said.
Labor's tax package has retained the 37 per cent bracket, which was set to be abolished under the original stage three plan.
Opposition Leader Peter Dutton deflected a question about whether the coalition would seek to abolish the 37 per cent rate if returned to power.
He said the coalition would develop a policy aimed at addressing the "silent killer" of bracket creep.
"It means that there's less incentive to work harder, it means productivity goes down," Mr Dutton told Sky News.
Former NSW premier Dominic Perrottet has called for negative gearing reforms to be considered as part of a wider debate about how tax changes could address housing affordability.
