The Liberal Party candidate under fire for referring to Chloe Shorten as a pig has gone to ground, after letters to the editor emerged in which she wrote private schools were far superior, and childless leaders lack empathy.

Kate Ashmor, the candidate for the Melbourne seat of Macnamara, refused to comment further on her remarks in which she said teachers in the private system were better than "the vast majority of those" in the public system. Later, a second letter to the editor she wrote emerged.

This is the third time Liberal candidate Kate Ashmor has attracted controversy for her views.

In it she said Bill Heffernan has raised an "interesting point" when describing the former Labor prime minister Julia Gillard as deliberately "barren".

"Being childless doesn't automatically invalidate one's opinions, nor does it make one unable to make a valuable contribution to society - far from it," Ashmor wrote to the editor of the Australian Financial Review in 2007.