Australian lawmakers overwhelmingly rejected a bill Wednesday that would have legalized gay marriage, and similar legislation looked unlikely to pass despite public support for same-sex marriage.

The House of Representatives voted 98-42 against the legislation, the first of four bills introduced to Parliament that aim to lift the country's ban on same-sex marriage. A separate bill was also being debated in the Senate on Wednesday.

Polls show that most Australians support gay marriage, but the Liberal Party-led conservative opposition coalition and many in the ruling centre-left Labor Party are against it.

"I think at some future time our Parliament will catch up with community opinion, just as it has on other issues," senior government minister Anthony Albanese told reporters after the vote. "When marriage equality occurs, people will wonder what the fuss was about."

Australian law defines marriage as a union between a man and a woman. The Labor Party lifted its long-standing opposition to gay marriage last year, but Prime Minister Julia Gillard remains opposed to it.

Gillard allowed Labor members to make a rare "conscience vote" on the bill Wednesday, which lets lawmakers vote by their personal beliefs without risking expulsion if they defy the party line. Opposition leader Tony Abbott did not give Liberal members that option.

Gillard's government holds a razor-thin majority in Parliament and several Labor members personally oppose gay marriage. The chance of any pro-gay marriage bill passing is, therefore, remote.

Finance Minister Penny Wong, who is gay, acknowledged in recent days that the legislation was unlikely to pass, but still argued passionately for its approval during the debate.

"If you subscribe to the principal of equality, as I'm sure most in the chamber would, then substitute 'same sex' for 'race' in this debate and see if it changes your view," Wong, who has a Chinese-Malaysian father and Australian mother of European descent, told lawmakers. "Just imagine if we told Australians today that they could not marry the person they love because of the colour of their skin."

The debate prompted one Liberal senator to step down as Abbott's parliamentary secretary after the senator made comments suggesting that permitting gay marriage could lead to calls for the legalization of bestiality and polygamy.

Abbott called Cory Bernardi's comments "ill-disciplined."

"They're views that I don't share," Abbott told reporters after Bernardi's resignation. "They're views that I think many people will find repugnant."

Gillard cancelled a scheduled address to a Christian lobby group this month over what she called "heartless" comments made by the group's managing director that suggested being gay was a bigger health hazard than smoking.

The Senate is expected to vote on its bill later this week.