A Parliamentary committee report on bills proposing the legalisation of gay marriage in Australia said on Monday that a tide supporting its realisation has been spawned and to legally prevent Aussie couples from formalising their union was both "un-defendable and unjust."

"The love between same-sex couples is no different," The Brisbane Times reported Labor backbencher Graham Perret as saying on today as he informed his colleagues that more than 70 per cent of those who participated in the online survey put up by the Social Policy and Legal Affairs Committee added their support for the private member bills now pending at the House of Representatives.

While stressing that he personally supports gay marriage, Mr Perret said that "it is for the Parliament to determine the passage of the bill and this report aims to inform the Parliament in its debate on the text and outcome of each bill."

Mr Perret, who chairs the committee, said the separate bills filed by Labor MP Stephen Jones and Greens MP Adam Bandt need only to undergo specific text tweaks and then the Parliament should consider them for debates and a formal vote.

Mr Bandt agreed that the country is ready for an overhaul on the concept of marriage as shown by the overwhelming support thrown by Australians on the inquiry but he reminded his co-members in the Parliament that their vote on the bills should be wholly based on what their conscience dictates.

"It should be done not just because it's popular but because it is right," The Australian quoted the Greens MP as saying today.

However, Greens leader Christine Milne cautioned her fellow lawmakers supporting the twin bill that forcing the proposal's debate too soon would lead to its demise, noting that officially the Labor-led government and the Coalition are against any attempts to give legal acknowledgment and protection to gay marriages.

It is best, Ms Milne suggested, for Parliament to wait for Liberal leader Tony Abbott to have change of heart and allow Coalition MPs conscience vote on the issue prior for the bills to be debated.

"I think it would be wise to avoid having the vote until such time as Tony Abbott decides to give his own members a conscience vote," the Greens leader was quoted by ABC as saying.

Prime Minister Julia Gillard was in agreement with Mr Abbot on vehemently opposing gay marriages but she allowed Labor MPs to vote on the issue basing entirely on their conscience unlike the Opposition Leader, who had warned that Coalition members would be penalised should they cross the Liberal-National line.

Aside from the seemingly solid stance of the Coalition against gay marriages, proponents of the private bills will have to contend to a strong Labor undercurrent on the legislation, media reports showed.

"Marriage, as the union between one man and one woman has been steeped in history, law, culture and religion for millennia. This is a fact which cannot be denied," a supplemental comment penned by Labor MPs Shayne Neumann and Mike Symon said in the committee report.

"We do not believe there is anything like sufficient community consensus which would justify changes to such a fundamental societal institution as marriage," the two stressed and as reported by the Australian Associated Press (AAP).

Also, while Liberal frontbencher Malcolm Turnbull had hinted that "the argument against same-sex marriage (was) less and less convincing," he conceded that supporting the bills was not an option for now.

"Politics is a team sport ... and we have decided on our side not to have a conscience vote ... so I won't be crossing the floor on this issue," Mr Turnbull told Sky News in an interview on Monday.