Cannes 2013: People will wonder why gay marriage took so long, says Liberace director The actor, who was diagnosed with throat cancer in 2010, said he was "eternally grateful to director Steven Soderbergh, co-star Matt Damon and producer Jerry Weintraub for inviting him to appear in the "great film." Choking back tears at a press conference, he said of the film: "It was right after my cancer. This beautiful gift was handed to me. I am eternally grateful to Steven and Matt and Jerry for a great film. Douglas, 68, plays Liberace in the critically-acclaimed film, which shows the charismatic pianist attempting to "adopt" the younger Scott while embarking on a sexual relationship with him. Speaking of the timing of the film, as Britain and the US debate legalising gay marriage, director Soderbergh said society is already "getting there" as he compared it to the civil rights movement. "It certainly seems coincidental," he said. It seems very timely and relevant. Whenever I think about issues like this I always try to think 50 years from now, what are we going to think about our attitudes. When this issue comes up, of equal rights for gays, I think - I'm hoping - in 50 years from now were going to look back and wonder why this is even a debate and why has it taken so long. We're getting there. It's all moving in the right direction. Speaking of the strain placed on Liberace's relationship in the 1960s from keeping it a secret, he added: "If it was now they wouldn't have to go through that." The film is based on a tell-all book of the same name, by Thorson, and shows the intimate relationship between the two men, detailing how he was left with nothing after being replaced in Liberace's affections. Matt Damon, who plays Thorson, has now suggested legalising gay marriage would mean the same situation could not happen again. "The guys around him at the time referred to it as a marriage," he said of the partnership. Had it been a relationship between a man and a woman, it would have been a marriage, they could have parted and come to some arrangement. Damon, who won an Oscar for his role in writing Good Will Hunting, added he and Douglas had used their own marriages as inspiration for the film. "What it felt like was a love story, a movie about a real, long-term relationship," he said. And I think that, for Michael and me, that was a way in. We're both married and we've both been in these relationships for a while and so we could relate. He also joked he had joined some of the world's greatest actresses, after getting into Michael Douglas's on-screen bed. The film, which was originally made for television, has been hailed by critics at Cannes where it is competing for the Palme d'Or. The Telegraph's Robbie Collin called it an "exceptional" biopic which "trickles and fizzes like Babycham."