Apple, the world's most valuable company, has thrown its weight behind marriage equality in Australia as debate over the federal government's plebiscite on the issue intensifies.The tech giant added its logo to the Australian Marriage Equality website on Tuesday.It joins hundreds other companies publicly backing the movement to legalise same-sex marriage, including the big four banks and Telstra, which came under fire earlier this year for appearing to renege on its support, only to then reaffirm it.In a statement, Apple said it "believes all people should be treated equally"."That's why we think all Australians should be able to marry the person they love," the company said.Other tech companies supporting marriage equality in Australia include Google, Microsoft, Twitter and LinkedIn.Apple's chief executive, Tim Cook, is openly gay and a supporter of gay rights and other humanitarian causes.He said on Twitter the legalisation of same-sex marriage in all 50 US states last year was "a victory for equality, perseverance and love".Thousands of Apple employees marched in last year's San Francisco Pride Parade. Happy Pride to everyone who turned out this weekend to celebrate!  
#applepride#pride2016pic.twitter.com/3GZlc9s6bl ??? Tim Cook (@tim_cook)   June 26, 2016 The Australian federal government promised it would hold a plebiscite on the legalisation of same-sex marriage in this country if re-elected.Attorney-General George Brandis is currently preparing a cabinet submission on the mechanics of the plebiscite. He has said the vote may not take place until next year.Labor and the Greens oppose the plebiscite, arguing for a parliamentary vote.Victorian Labor Premier Daniel Andrews has called for Prime Minister Malcolm Turnbull to grant MPs a conscience vote.