Former Treasury economist Peter Downes is making a last-ditch plea for Jim Chalmers to walk back his plan to curb negative gearing, warning it will push up rents.

The government assumes investors will calmly migrate from established housing into off-the-plan developments. But investors are not pieces on a Treasury chessboard.

New data shows more than half of the nation’s 2.3 million investment properties are running at a cash-flow loss, emboldening Labor’s move to curtail negative gearing.

Former Treasury economist Peter Downes is making a last-ditch plea for Jim Chalmers to walk back his plan to curb negative gearing, warning it will push up rents.