Federal Labor has seized on the release of Treasury documents stating its policy to tighten tax breaks for property investors would have a small impact on house prices.
The documents the ABC obtained contradict the Turnbull government's claim the negative gearing changes would be a "sledgehammer" to Australia's economy.
Shadow Treasurer Chris Bowen said the document exposed the government's attack on Labor's housing affordability policies "as little more than outright lies".
The policy was a hot button issue during the 2016 election campaign.
"The likes of Malcolm Turnbull, Scott Morrison and Peter Dutton still chose to dial up the political rhetoric in a poor attempt at a scare campaign," Mr Bowen said.
The documents say Labor's policies could introduce some downward pressure on property prices in the short term, particularly if the commencement of the plan coincides with a weaker housing market.
"Overall, price changes are likely to be small, though the composition of ownership may shift away from domestic investors," Treasury officials wrote.
Asked if the Turnbull government had lied about the impact of Labor's policy, Liberal frontbencher Simon Birmingham said, "Absolutely not".
"It's two-year-old analysis; it shows indeed, there would be downward pressure, which is exactly what the government has been saying all along," Senator Birmingham told ABC Radio.