Majority of submissions to a Senate committee that investigated marriage equality are in favour of a legislation that would permit gay couples to marry. Almost 60 per cent or 46,000 submissions that the committee received backed the legalisation of same-sex union.

Based on the submissions as well as results of its probe, the committee recommended the amendment of the definition of marriage and a debate into the Marriage Equality Amendment Bill with the view of passing a law in favour of gay marriages.

Senator Trish Crossin, chairwoman of the committee, recommended that MPs be allowed a conscience vote on the issue. Ms Crossin is a member of the Australian Labor Party which has allowed a conscience vote.

However, the Coalition is still insisting that members tow the party stand, which led two Opposition senators, Simon Birmingham and Sue Boyce, to break ranks and back the committee's recommendations.

"We found as a committee that it is simply not relevant anymore to specify that (marriage) is an institution just for men and women alone," ABC quoted Ms Crossin.

"This is an institution now that this society has recognised can be for two men or two women, for a man and a woman, for people who are transgender," she added.

However, the committee was not unanimous in its recommendation. Gary Humphries, a Liberal senator and member of the committee, wrote a dissenting report which was also signed by Michaela Cash and Eric Abetz. Mr Humphries insisted that the tone of the majority report did not take into account evidence.

But Greens Senator Sarah Hanson-Young, who authored the bill, countered that the committee's evidence, that the time for marriage equality has arrived, was overwhelming.