Matt Damon, declaring, "This is the best time I have ever had on a chat show," talks about Mark Wahlberg's recent exuberant appearance on Graham's sofa. Revealing their fans often mistake the actors for each other, he says, "I get confused with him all the time. We talked about it years ago because it kept happening. We have a deal. And the deal is, if you're mistaken for the other guy you have to be extremely polite. I can't ruin his name, so when I'm Mark Wahlberg I have to be on my best behaviour!"

Talking about the joys of working with George Clooney, Matt says, "He has been playing pranks for 15 years. To give you an example, his dad is in the movie and George runs it just for him. As the credits rolled, it said, 'In loving memory of Nick Clooney,' his dad says, 'What the hell George?' and George goes, "Well dad, the movie doesn't come out for six months. It's much cheaper to take these things off the credits than put them on!' So that's who you're dealing with and you have to understand that going into a movie. It is so funny to him."

Asked about falling out with the original producers of Good Will Hunting, Matt says, "We were convinced they weren't reading the re-writes so we started adding random scenes, first a love scene and then a gay sex scene that was gayer than anything in Liberace - it was full on and they didn't comment! Finally we took it to Harvey Weinstein, who really saved us, and the first thing he said was, 'I have one note. The sex scene has to go!"

And on getting into the character of Liberace's lover in ]Behind The Candelabra, he says, "The clothes were really helpful, it was a great role. Michael and I concentrated on the relationship between them and not the sex, we both work in the arts and have lots of gay friends so we didn't want to mess it up." Talking about the sex scene, he says, "It's an optical illusion. It was filmed from the end of the bed and we had our pants on!"

Talking about his love of Downton Abbey, Matt says, "My wife is an addict. It's a problem. We were supposed to watch it together and I came to bed one night and she said, 'I've just watched six of them - I'll tell you what happened!' She wanted to watch the seventh and didn't want to go back to the beginning. So she's done the whole thing and I am on my own."

Bill Murray, asked if he watches Downton, says, "I'm really slow so I miss these shows and I really look forward to getting a serious flu or something so I can get the set and watch the whole thing."

Living up to his eccentric reputation Bill is reminded of an incident while at the recent Berlin film festival. Matt recalls, "He is so cool. We were due to have a cast dinner and Bill walks up and says, 'I might miss dinner tonight,' and I'm like, 'Are you not feeling well?' and he says, 'No, I'm going to go to Prague.' I said, 'It's five hours away by train, you're going to get there at midnight, and he was like, 'Yeah, but I've never been there.' He was back for nine the following morning, spot on time for the press!"

Asked what his character said to Scarlet Johansson's in the famous closing scene of Lost in Translation, he says, "I said something but he didn't need to say anything and it wasn't important what was said. It was just between them but it would have been about love."

On preparing for the role by using a phrase book called 'Making out in Japanese', he says, "It was great. I would take the book with me to dinner at a sushi bar and say to the chef things like, 'Can we get into the back seat?' 'Do you have a curfew?' And, 'Do you mind if we use protection?' And these guys had big, big knives! I had a lot of fun with it."

Hugh Bonneville says he too is often mistaken for other people, "There is a confusion. In my younger days, when I had cheekbones, it was Colin Firth and latterly it's Paul Burrell!"

Revealing he may not have been George Clooney's first choice for his new movie, Monuments Men, Hugh says, "I got a very dry letter through my agent saying, 'Dear Hugh, for your attention... produced by... followed by millions of names of the producers and starring Bill and Matt and everyone else and then at the bottom another name for my part which they'd failed to wipe out!" Refusing to be drawn on who the actor was, he adds, "It's fine, these things happen and I was thrilled."

Paloma Faith performs Can't Rely On You before joining Graham for a chat and spot of tomfoolery with her fellow guests.

And finally, with the help of Matt and Hugh, who tells his own story in the Red Chair, Graham pulls the lever on more foolhardy audience members brave enough to tell their tales.