It was both a dark and bright day for gays and lesbians in Australia on Wednesday as Parliament rejected the same-sex marriage bill, while Liberal Senator Cory Bernardi resigned as parliamentary secretary for derogatory remarks he made against gay marriages.

On a vote of 98-42, the controversial measure was rejected despite Labor allowing party members to vote according to their conscience. Among those who voted against same-sex marriage were Prime Minister Julia Gillard, Treasurer Wayne Swan, former Prime Minister Kevin Rudd and Coalition leader Tony Abbott.

However, pro same-sex union groups are not giving up the fight, said gay rights advocate Shelley Argent.

"We're not giving up. If something's worth having, it's worth fighting for. We'll see this reform happen state-by-state and territory-by-territory and that'll continue to put pressure on the federal government," ABC quoted Ms Argent, who has a gay son.

Besides the expected defeat of the gay union bill, the bigger news of the day was the decision of Mr Bernardi to resign a day after he warned that approval of the measure could lead to possible recognition of bestiality as marriage.

"There are even some creepy people out there, and I say creepy, who are afforded, unfortunately, a great deal more respect than I believe they should, who say that, you know, it's OK to have consensual sexual relations between humans and animals," ABC quoted the senator.

Indicating that he will continue to speak against same sex marriage, Mr Bernardi warned, "The next step, quite frankly, is having three people that love each other should be able to enter into a permanent union endorsed by society, or four people."

Shadow communications spokesman Malcolm Turnbull stressed that Mr Bernardi does not represent the views of the Liberal Party. Mr Turnbull is in favour of gay marriages, but followed party stand and voted against the bill.

Mr Abbott admitted he pressured Mr Bernardi to step down which is part of party discipline but maintained that the controversial senator is a "decent bloke with strong opinions."

"But discipline is critical. Team play is vital. And that's what Cory has had some problems with. And that's why I thought it was very important to act quickly and decisively," Skynews quoted Mr Abbott.

Mr Bernardi admitted he quit his post in the interest of the coalition, but did not apologise or expressed remorse for his bestiality comment. On the same day, he left Canberra to attend a conference of young conservatives in Oxford, England.

But even British Liberals are keeping their distance from Mr Bernardi.

"We haven't organised this event and are not in control of who attends. We strongly condemn Mr Bernardi's comments which don't reflect (Prime Minister) David Cameron's or the Conservative Party's viewpoint in any way," Mail Online quoted a Conservative Party spokesman.

RELATED STORIES