Assistant Immigration Minister Matt Thistlethwaite made the comments during a News24 appearance. Picture: NewsWire / Nikki ShortA property is in negative equity when its value is less than the owner's remaining mortgage balance. Nationals leader Matt Canavan has accused Labor's policies of driving a lack of confidence in the property market. Picture: NewsWire / Martin Ollman. Acting Prime Minister Richard Marles insisted there were a 'lot of factors' contributing to changes in house prices.