Same-sex marriages are still illegal in Australia, and earlier this month (Oct16) singer Aussie Kylie Minogue's British fiance Joshua Sasse launched the Say 'I Do' Down Under campaign to put pressure on the government to legalise same-sex unions.

The cause has received celebrity support from Margot Robbie, Dolly Parton and Jake Shears from the Scissor Sisters, among others. And now the Jurassic Park star has voiced disbelief that politicians are stalling on the issue.

"I can't believe we're talking about this at all," Sam ranted in an interview featured in the Mixed Grill segment on Australia’s Channel Nine's Today news show. "Sixty four per cent of Australians are for marriage equality, most politicians are for marriage equality. I don't think it's any business of anyone who should get married and who shouldn't.

The 69-year-old actor, who is currently in Australia filming Thor: Ragnarok on the Gold Coast, Queensland, grew up in New Zealand, where a marriage equality law was passed in 2013. More than two dozen countries around the world have since followed suit, including the United States and the United Kingdom.

Sam criticised Australia's parliament for its indecisiveness on the issue and shared his incredulity that the issue of gay marriage was still being debated.

"Why don't they just get up and pass the bill? What's the matter with this constipated parliament?" blasted the Peaky Blinders star.

According to Britain's Daily Telegraph, Australia are planning to address the issue next February (17), with a plebiscite, a non-binding public vote.

However, last week Opposition Labor Leader Bill Shorten moved to block the plebiscite proposed by Prime Minister Malcolm Turnbull.