In a blog post , the HRC described Australia as "the next country with an opportunity to approve nationwide marriage equality".

"After today's US decision, the world will now focus on whether the Australian Government will allow its members to vote with their conscience on marriage – despite Prime Minister Tony Abbott's steadfast reluctance to allow such a vote," they wrote.

Advocacy group Australian Marriage Equality (AME) said they would be working with the HRC in the coming weeks and months to raise the global profile of the campaign.

National director of AME Rodney Croome welcomed the HRC's support for the Australian campaign.

"It will muster support across the world and highlight how far Australia is falling behind," he said. "Now marriage equality has been achieved in the US, all eyes will be on Australia with the hope we are next."