The Government would be better leaving negative gearing in place for many reasons. Negative gearing basically allows plenty of rental properties available in the market place and if removed would cause rental properties to dry up very quickly.

Another problem would be a mass exodus from rental properties causing a massive glut of properties on the market and causing a certain price correction. Even if corrected by 20% most renters would still not be able to purchase these properties because the banks would surely raise their interest rates in such an uncertain market and they would definitely require a much larger deposit.