The Graham Norton Show

Stephen Mangan talks about celebrity spotting, Emilia Fox says her daughter will not be following in her footsteps, Johnny Vegas talks about posing naked and Jess Glynne performs her brand new single live in the studio.

Stephen Mangan, revealing some embarrassing encounters with famous people, says, "I once introduced myself to Robert De Niro and I was so nervous I said, 'Hello, I'm Robert De Niro,' to which he responded, 'No, I'm Robert De Niro!' I ran up to a woman in the street convinced that I had worked with her somewhere and it turned out to be Meg Ryan, and the other day I greeted someone like a long-lost friend and I realised it was Madge from Neighbours!"

Talking about his upcoming Channel 4 series Hang Ups, he says, "It is improvisation in a different way - there was no script at all. It was very scary to turn up for a day's filming and not know what you'd do and where you would end up. I think everyone, without exception, came in terrified and left really enjoying it."

Joking that he is a lazy parent, Stephen reveals his bedtime ruse, "I've recorded a lot of audio books so we had a lot of fairy tales on CD and I am ashamed to say that with our first child, I would press 'play' and back out of the room. I wonder if he thought it odd that every story started with, 'Read by Stephen Mangan.'"

Emilia Fox, talking about the new (22nd) series of Silent Witness, and asked how much she really knows about pathology, says, "It is shameful actually. This is my 14th year and I think in that time I could have become a pathologist but in reality, I would be very ill-equipped to do anything. I've actually had sleepless nights trying to remember complicated drug names and procedural terms."

Asked if she thinks her daughter Rose will following in the Fox dynasty's acting footsteps, Emilia says, "Categorically not. The other day when she was telling us about being born, going to school, going to university and getting a job, one of the family asked her if she would go to drama school and her reply was, 'Acting is not a job it's an activity.' I had to agree with her!"

Johnny Vegas, talking about posing naked ala Demi Moore, says: "It was terrible - I was close to tears because I am actually very shy. Nobody told me I would be naked. As I was putting my trousers back on I looked up and there was a woman in the office opposite typing and just staring at me. I just mouthed 'Sorry' at her. And, that was the first picture my mother-in-law ever saw of me!"

Discussing irrational fears, Graham's guests (and some audience members) reveal theirs. Stephen admits, "I have a few but used to be terrified I would drop - or actually throw - one of the babies." Emilia says, "I don't like flowerpots - the unglazed ones are horrible. I wouldn't run away, but I wouldn't pick one up either. I have the same feeling towards belly buttons!"

Johnny says that one scene in his and Emilia's BBC One series, Home From Home, reduced him to a quivering wreck, "We were in a hot air balloon and as we went up I got lower and lower into the corner of the basket. I couldn't speak and started making terrible grunting noises. Then I became terrified that Emilia was going to fall over the side. It was terrifying."

And on Elaine Paige playing his mum in the new series, he says, "It was a minor stroke of genius casting her. She is fantastic and my mum loves her!"

In a TV exclusive, Jess Glynne performs I'll Be There live in the studio before joining Graham for a chat about her new single, released today, and new album.

Asked about the hiatus between her 2015 album and her new single, she says, "I have been on the road for a good two years, which was a lot of hard work and for the past six to 12 months I have been writing and chilling - having a laugh, going to the pub and seeing friends and family."

Talking about her upcoming album, she says, "It's coming. It's ready but not quite. It should be out in the autumn."

On the success of having so many number one singles, she says, "It is weird but amazing and I am so grateful." Asked about her music appearing on ads, she jokes, "It's quite annoying. You hear them all the time."