Across the nation overall, Moody's expects house prices in major cities to fall 7.7 per cent this year, while apartments will see a smaller 4.3 per cent decline, according to the ratings agency report.
The news isn't great for Perth either, with house values tipped to decline 7.6 per cent in 2019.
The property downturn could be made worse by changes to negative gearing and further tightening in lending restrictions.
There's better news in Brisbane, with the worst "likely over" for the Queensland capital, according to the report. House values are set to see a correction in 2019 and strength in East Brisbane.
Values in Brisbane's apartment market are tipped to recover 0.9 per cent this year.
Adelaide's housing market will remain stable, with house values forecast to rise 1 per cent in 2019 following a 1.9 per cent gain in 2018.
In Darwin, a further 13.1 per cent slump is tipped for 2019.
Hobart is tipped to end next year with small decreases in house prices over 2020 and 2021.
Labor's plan to abolish negative gearing on existing properties for new investors could put a halt to a near-term rebound in the market.
"If this policy were implemented within the first year of the Opposition entering office, already-slowing conditions in the investor segment of the market would be exacerbated," the analysts wrote.
"As investor participation had already slowed, national home values would be expected to reach a slightly deeper trough and have a slower recovery, particularly in the markets where investor participation is higher than the national average, including Sydney, Melbourne and Brisbane."
Moody's expects the Reserve Bank to keep the official cash rate on hold at 1.5 per cent until the middle of 2021.
Property prices are still around 20 per cent higher than they were at the start of the property boom in 2013.
