Television star Shaun Williamson turns his talents to the role made famous by Marlon Brando in Guys and Dolls, writes ANGIE JOHNSON

What have Ricky Gervais and Frank Sinatra got in common? The answer is Shaun Williamson, the multi-talented performer who features in Gervais's classy comedy Extras, and who is reprising the Frank Sinatra's famous role of Nathan Detroit in the forthcoming production of Guys and Dolls at the New Theatre in Oxford.

Originally this production started out at the prestigious Donmar Theatre in London, where it picked up several Olivier Awards. Taken on a new national tour, the production has been wowing audiences at its opening venue, Southampton's Mayflower Theatre.

It was in Southampton I caught up with Shaun, who is one of the friendliest people imaginable. I asked him about the varied career he has had over the years in stand-up comedy, soap opera, musical theatre, and sit-com.

"I think it's because I have a wide background. I went to drama school when I was 27, worked with bands and was a Blue Coat with Pontins. I did everything there, as you can imagine. Performing, bingo-calling, compèring the Lovely Legs Competitions - you name it, we did it. My drama school, the Webber Douglas Academy, was very wide-ranging and provided an excellent training. I particularly loved doing Shakespeare and the classics when I was there."

Williamson's role as Nathan Detroit, though far from Shakespeare, is key to Guys and Dolls. He's the operator of the The oldest established permanent floating crap game in New York' and a key player in the illegal gambling fraternity of 1920s New York.

Based on a short story by Damon Runyon, the plot revolves around Nathan finding a secret venue for the game' when the heat is on from the cops, while trying desperately to avoid getting married to his long-suffering fiancé Adele.

It's a lovely, funny tale of a bunch of colourful ne'er-do-wells and the beautiful Salvation Army girl who tries to turn them to the path of righteousness. Written by Frank Leosser, the show is full to the brim with hit numbers such as Luck be a Lady, Sit Down Your Rocking the Boat and the title song Guys and Dolls. It is a 24-carat musical of the kind they just don't seem to write these days, more's the pity.

No stranger to musical theatre, Shaun has in recent years appeared as Monty the DJ in the touring production of Saturday Night Fever, and as the Narrator in The Rocky Horror Show, where he took over from Michael Aspel who played the role on its last visit to Oxford. I mentioned I thought Aspel sometimes looked a bit uncomfortable with the riotous audience participation traditional with this cult show (I remember one woman continually shouting "I love you, Michael" and another "Get your trousers off!"). But Williamson wasn't fazed by any of that.

"That's where my stand-up experience came in useful. I loved all that about the show. It was a lovely job."

He is clearly just as much enamoured with Guys and Dolls.

"It's a great musical and the show is going like a dream. The audiences are loving it so much.

"I read Damon Runyon's original stories before I began and you can tell that the brilliance begins right there at the beginning. They are such great characters and plots. Then you add the music and the songs and it's unbeatable."

The dancing is also a big feature of this show and Shaun confessed that they had given him, "a big, complicated routine. I was nervous at first, but so far it has gone really well".

I suggested that by the time it comes to Oxford he will be as polished as Astaire, which made him chuckle.

"I am really looking forward to my time in Oxford. I've never been before. But I love history and am planning to visit the colleges and cathedral. It will be fantastic."

Talking of history, I brought him back to his earlier career when he played Barry on EastEnders for nine years.

"Like any job long-term job, there are times over the years when you love it and other times not so much. But it was an incredible experience. You work with such great casts."

I wondered if he ever worried he would be typecast because of his long association with that part?

"That is always in the back of your mind when you do a long-running show. But then, how can you complain when because of it Ricky Gervais and Stephen Marchant then come along and offer you a chance to be a part of a show like Extras."

In Gervais's hit series, Williamson plays a character known only as Barry from EastEnders', but in real life he has managed to avoid the pitfalls of the post soap-opera oblivion that this alter ego and so many others have fallen into in.

"I think it helps if you can sing," said Shaun. "Look at the shows in the West End - 60 per cent are musicals."

But I suggest to him that is not the only reason for his continued success because as an accomplished all-rounder he has never been afraid to try something different. His answer is refreshingly modest.

"That comes back to the great training I had. I learnt so much in the early days, and that's what gives me so many strings to my bow. That gives you longevity in your career."

I certainly expect to see Shaun around for a long time, either on stage or on the box. He is also about to make his first feature film, Daylight Robbery, a British crime caper.

I wondered what he thought his two children, Sophie Mae and Joseph, would think of my dad the movie star'?

"Well that will be interesting to see their reaction because they are too young to have seen me on EastEnders. So we shall see."

We shall indeed see Shaun when he comes to the New Theatre in Guys and Dolls from Tuesday until May 26. For tickets call 0870 606 3500.