Two openly gay MPs in Australia have backed calls for gay marriage.

Senator Penny Wong and Greens leader Bob Brown spoke about why gay people should be given full marriage equality.

Ms Wong, appearing at a party conference at the weekend, introduced a motion in favour of same-sex marriage.

“I will be advocating for our party to support equality including to in relation to marriage or same-sex couples and I do so because I have a deeply held commitment to equality,” she said.

The finance minister was criticised earlier this year for failing to show support for the issue.

Meanwhile, Mr Brown, whose party is pushing for a change in the law, said that although he strongly supports marriage equality, he has not considered getting married to partner Paul Thomas.

He said: “Paul and I registered our partnership in Tasmania surrounded by a group of friends. It’s not something that I’ve really considered.”

Prime minister Julia Gillard is to allow her party a conscience vote on the issue at next year’s conference.

A recent poll carried out for the Greens found that 57 per cent of the public were in favour of the change.

Of the 37 per cent who were against the change, 16 per cent were opposed and 21 per cent were strongly opposed.