From July 2027, negative gearing will be scrapped for all homes except new builds, while the 50 per cent capital gains tax discount will be abolished for existing properties in favour of a new scheme tied to inflation.
The federal government has pitched the changes as an effort to help younger Australians - many of whom may have been locked out of the property market - to buy their first home.
Close to half the electoral roll is now made up of millennials and Gen Z - a group which analysts say Labor is trying to win over with its controversial budget.
The housing tax changes were designed to counter accusations the government was being too timid with its mammoth 94-seat majority in parliament, Monash University politics expert Zareh Ghazarian told AAP.
"The risk here, of course, is that it will offend those who were not expecting these sorts of changes, and those who have established a long history of rental investments," he said.
Associate Professor Ghazarian said the government could "lose some political skin" for breaking its promise not to touch negative gearing or capital gains in the lead-up to the last election.
"But in the longer term, the calculation must be that this is going to be a winner," he said.
The opposition has promised to repeal the changes if it wins the next election, casting them as an assault on aspiration.
"We'll do whatever we have to do to ensure that these taxes are not imposed on Australians," Opposition Leader Angus Taylor told ABC TV on Wednesday.
"The hostility will be enormous, and I think the government will be forced to recant on significant parts of this, or all of this," he said.
Prime Minister Anthony Albanese said the coalition was repeating the same political mistake it made in the lead-up to the last election, when it promised to repeal a modest tax cut announced in the 2025 budget.
"It's a repeat of what happened one year ago... these geniuses are going to go to the election saying that they will repeal young Australians getting a fair go," he told parliament on Tuesday.
