One day, he'd like to return the favour.

But for Mr Bearman, 26, there is more than a proposal and a few jitters standing in the way of his special day.

He and his partner, James Pollack, 27, are among the thousands of gay and lesbian couples throughout Australia who cannot marry because the law will not allow it.

The couple hope today's historic move, in which Throsby MP Stephen Jones will introduce a private member's bill to legalise same-sex marriage, will take them a step closer to the recognition they want and believe they deserve.

"One of the best things about Trevor and [his wife] Denise's wedding was being able to see them declare publicly and intimately their love for each other through marriage and to have it socially and legally recognised and accepted," Mr Pollack said.

"As a couple, that's what we want, and it's what our family and friends want for us as well."

The Dapto couple have already made a lifelong commitment to each other - they became engaged mid-last year - but remain frustrated and hurt their relationship cannot progress further.

The Gaskells say they share that frustration.

"I just don't think anyone should have the right to tell someone else who they can or can't marry," Mrs Gaskell said.

For Mr Pollack and Mr Bearman, the series of events that will unfold in Canberra today signals a real turning point in the fight for marriage equality.

"I feel really proud that it's our MP that is leading this," Mr Pollack said, but he acknowledged Mr Jones was likely to face strong resistance from some fellow Labor MPs and the Opposition.

He urged Mr Jones to remain focused, committed and strong in the wake of the backlash.

"We'd really like to say thank you to Stephen - for listening and recognising our relationships are valid as well," Mr Pollack said.