Labor's candidate for the seat of Melbourne, Luke Creasey, has been forced to withdraw from the contest over a series of lewd social media posts about lesbians and "roughly" taking someone's virginity.

Former Labor candidate for Melbourne Luke Creasey. Credit:Justin McManus

Mr Creasey's removal capped off a messy week for both major parties with three Liberal candidates, two in Victoria and one in Tasmania, also forced off their party's ticket after extremist comments they made online came to light.

Mr Morrison suffered the biggest blow with the resignation of Jessica Whelan, who was running in Lyons, a marginal Tasmanian seat the Liberals had targeted as a possible pick up to help it form majority government.

After initially claiming anti-Muslim comments made in her name had been manipulated, Ms Whelan admitted that she was responsible for other comments she had made on Facebook that came to light overnight Thursday.