Labor's Help to Buy program will go to a vote in the House of Representatives on Wednesday.
Under the shared equity scheme, the Commonwealth would contribute 40 per cent of the value of a home for a new property, or 30 per cent for an existing one, allowing first homebuyers to enter the market with as little as a two per cent deposit.
But the passage of the scheme remains uncertain, with the Greens opposing it and arguing it would drive up housing prices.
Greens leader Adam Bandt said the party would reserve its position on the issue until it reached the upper house.
This housing and rental crisis is breaking people. Labor needs to wake up.— Adam Bandt (@AdamBandt) Instead, Labor's pushing up rents and house prices.February 26, 2024
"The housing crisis is breaking people," Mr Bandt told the ABC on Wednesday.
"You've got renters who are skipping meals to scrape together a deposit for a first home, only to find that house prices have gone up so much that by the time they save, their money is not enough.
"You've got first home buyers turning up to auctions and getting outbid by wealthy property investors who are getting massive subsidies."
The minor party is instead calling for changes to property tax breaks such as negative gearing and the capital gains discount - which it says would address some of the causes of the housing crisis.
Housing Minister Julie Collins said the scheme would benefit first home buyers looking to enter the property market as well as boost supply.
Housing Minister Julie Collins says the scheme would provide "life-changing support". (Lukas Coch/AAP PHOTOS)
"This is life-changing support, this will help 40,000 Australians into home ownership," she told parliament on Wednesday
"(The Liberals and Greens) are supposed to support Australians into home ownership, yet they don't when given the opportunity (in parliament) by voting against Help to Buy and denying those tens of thousands of Australians the great Australian dream."
Prime Minister Anthony Albanese also hit out at the Greens opposition to the proposal, saying the minor party had previously supported a similar first-home buyer scheme.
"The Greens went to the last federal election saying they would support and implement ... a shared equity scheme," he told ABC.
"This is good policy, this is about helping people into home ownership."