A Victorian Liberal candidate has resigned after being embroiled in an extremism row, publicly endorsing an attack on his party colleague, Goldstein MP Tim Wilson, as a "notorious homosexual".
Peter Killin complained to fellow right-wing Liberal Christian activists in December 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, who was contesting the Labor-held seat of Wills in Melbourne's inner north, made his remarks in the comments thread of the blog of Christian-right blogger Bill Muehlenberg.
The party confirmed his resignation on Wednesday afternoon.
The candidate's comments came in response to a post by another commentator, Michael Taouk, who said he was not in the Liberal Party, calling for the "Liberal grassroots" to "remove preselection from that notorious homosexual Tim Wilson".
Mr Taouk wrote: "No true Christian can fight on the same side of that man."
In response, Mr Killin wrote: "Your observations about Mr T Wilson, federal member for Goldstein are most pertinent at this point. Many of us will recall he was the openly homosexual who proposed to his boyfriend in parliment [sic]."
Mr Killin went on to exhort his fellow activists to greater efforts to prevent gay people from becoming Liberal members of Parliament, noting that Mr Wilson's preselection was won by a very narrow margin.
"ONE LOUSY VOTE! So, if you and I were there to participate in preselection the result = no homosexual MP," Mr Killin wrote.
"Thats what grass roots is - you and me - not someone else!"
Elsewhere in the blog post, Mr Killin railed against "evil laws" such as "Abortion, Euthanasia" and "Gender ideologies" and urged his fellow activists to "infiltrate, influence and impel" to "change the party from within".
Mr Wilson said on Wednesday that his reaction would be in keeping with his own Christian-inspired values.
"I'm culturally Anglican," he said. "So I learnt as a young boy to turn the other cheek and leave judgment to others.
"I've been absolutely consistent from preselection to election to seeking re-election that I'm a forward-looking, modern Liberal proudly representing a forward-looking modern liberal community and that won't change."
Mr Killin was brought in to contest Wills this month after the originally selected candidate was sacked over concerns about her eligibility to sit in Parliament under Section 44 of the constitution.
Prime Minister Scott Morrison said Mr Wilson was an "outstanding" MP.
He conceded the party's vetting procedures had fallen short.
"For the Liberal Party in this day and age when there is social media, multiple posting, that represents new challenges in the vetting of candidates," he said.
"This is something I will be expecting the party to be working on and improving their processes."
Mr Killin's attack on Mr Wilson comes to light after the sacking of Jeremy Hearn, another Melbourne-based Liberal candidate, over extreme anti-Muslim comments, also made online.
Mr Hearn is the fifth Victorian Liberal candidate to be dumped from the party's ticket.
One Liberal source said the comments were outrageous and bigoted.
"The party is about the rights of the individual, not the rights of bigots," the source said.
"Bigots are not welcome in the Liberal Party and that's the way it should be."
Mr Killin has been contacted for comment.