Thanks a lot Spamalot! Marcus Brigstocke so enjoyed strutting the stage on tour as King Arthur in Monty Python’s Spamalot that the comedian, broadcaster, writer and actor decided he wanted to do more theatre work.

Now, York Theatre Royal artistic director Damian Cruden has granted him that chance in the role of station master Albert Perks in the 2011 run of The Railway Children in the disused Eurostar terminal at Waterloo Station in London.

“I saw the show last year just before Christmas when the first run was about to close,” says Marcus. “We came with our kids and the in-laws, and I didn’t really know what to expect in advance.

“I’d seen the film and had a vague recollection of it, thinking it was for girls, but I was excited to see it in a station and I have to say it blew my mind.

“It was such a beautiful way to tell the story with the cast going up and down the tracks and the audience on the platforms either side.”

Marcus “unleashed” his agent on landing him the part of Perks and he made the most of his time in York last November while on his regal tour as King Arthur. “I met Damian Cruden when I came to do Spamalot at the Grand Opera House,” he recalls.

“I knew someone who had worked with him, Pandora Clifford, and she said ‘you must meet him’, so I made a call and we met up for a cup of tea and an informal chat.

“He made the time for me and gave me a tour around the Theatre Royal, and on his recommendation I came up to see the pantomime – which was an unforgettable experience, if a little terrifying, though I was all right as I was beyond Berwick’s reach!”

Marcus duly auditioned for Perks. “I had a strong desire to get that part, so that was that!” he says. “I don’t get nervous in the audition, though I probably should, but primarily they’re looking to see if you’re right for the role, and if you get the audition but don’t get the role it’s probably because you’re not right for it, rather than being terrible in it, so I kind of don’t worry beforehand.”

Likewise, mastering a Yorkshire accent for the reserved, warm and kindly Perks held no qualms for Marcus. “The origin of my stand-up was doing accents and that’s something that I always really enjoyed,” he says, not unduly worried that “die-hard Yorkshiremen might say ‘where the hell’s he coming from?’.”

He is relishing joining a show with Olivier Award-winning pedigree. “On a technical level, it’s the rolling stages that so impressed me,” he says.

“Obviously, when the steam train arrives, that’s a magnificent moment but you know that’s coming. What you don’t know is how beautifully the scenes move along the tracks, and no matter where you sit you can see it perfectly,” he says.

Whereas Damian Cruden directed the original production in its two summers at the National Railway Museum and in its first transfer to Waterloo, the 2011 show is in the hands of Mark Babych, former artistic director of the Bolton Octagon.

“Damian is coming down for a look but Mark is in sole charge,” says Marcus.

“It’s funny doing a piece like this which pre-exists and works already, and so you don’t want to change it, as there’s a train coming, and if you change it, you’ll die!

“But at the same time you have to find your character.” Well, witnessing the picture, he has certainly cultivated magnificent facial topiary.

Marcus has been finding other characters too but in a different cause: he has just launched his book God Collar at the Hay-on-Wye Book Festival.

His upcoming diary is as busy as ever. “I’m in this show until September and it may be that I’ll be able to do it a little longer but I need to write my new stand-up tour to go out on tour next year and there’s a number of other things coming up too,” says Marcus. “I’m going back into Spamalot for four weeks at Brighton, where they’ll be running it over the panto season!”

• York Theatre Royal’s re-opened transfer of The Railway Children runs until September 4 at the 1,000-seat Waterloo Station Theatre, London, until September 4. Box office: 0871 297 0740.