Same-sex marriage has come under the spotlight in Australia this year. It was a key talking point during the country's federal election in June, and high-profile celebrities, from Margot Robbie to Kylie Minogue , are publicly backing it.So, why is it in the headlines?Same-sex marriages are not currently recognised by the Australian government because the country's Marriage Act defines marriage as between "a man and a woman", rather than "two people".Prime minister Malcolm Turnbull has promised to hold a non-binding plebiscite, i.e. a direct vote of the Australian electorate, on the issue.However, on Tuesday the country's Labor opposition MPs voted against holding a national vote . Critics of the plan, including many campaigners backing marriage equality, believe a plebiscite risks unleashing a torrent of homophobia and would be expensive.Instead, gay rights campaigners want parliament itself to vote on legalising gay marriage. Of 5,500 LGBTI Australians surveyed by Just Equal in July, 85% opposed a plebiscite and 62% would rather wait for a parliamentary vote.One woman, Georgina Hibberd, an Australian who married a woman in Hawaii several years ago, said she wouldn't want their 13-year-old son to be exposed to any homophobic rhetoric. "I can handle it, I've done it all my life but my son - that's another matter," she told the BBC The Australian Senate will still vote on whether a plebiscite should be held, but it is unlikely to pass after opposition MPs' announcement yesterday and the situation probably won't be resolved before this parliament ends, the BBC reported Numerous celebrities have come out in support of marriage equality in Australia in recent weeks. Margot Robbie showed her support for the cause while hosting Saturday Night Live a couple of weeks back.She wore a t-shirt in support of Australians 4 Equality , a group campaigning for marriage equality to be reached through a free parliamentary vote rather than a plebiscite.