Victorian Liberals had a disastrous day in the federal election campaign when two candidates were obliged to resign over homophobic and Islamaphobic comments.

Wills candidate Peter Killin resigned on Wednesday after publicly endorsing an attack on party colleague, Goldstein MP Tim Wilson, as a "notorious homosexual".

Mr Killin complained to fellow right-wing Liberal Christian activists in December last year that not enough of them had shown up at a preselection vote for the Liberal heartland seat of Goldstein in 2016 to prevent Mr Wilson from being selected to represent the seat.

Mr Killin made his remarks in the comments thread of Christian-right blogger Bill Muehlenberg.

Mr Killin's online attack came to light after the resignation of Jeremy Hearn, Liberal candidate for Isaacs, over extreme anti-Muslim comments that were also made online.