The endlessly fascinating Willy Wonka on the Southampton stage

Charlie and the Chocolate Factory The Musical comes to Southampton’s Mayflower Theatre from August 16-September 3, and every night of the run, as Gareth says, he will be discovering more and more about Roald Dahl’s fabulous creation.

Based on the iconic story, the spectacular stage show follows the hit West End and Broadway productions to combine the memorable songs from the original 1970s motion picture (The Candy Man and Pure Imagination) with all-new numbers from the multi award-winning songwriters of Hairspray.

Gareth is certainly looking the part with his Willy Wonka moustache and goatee: “It took about three months to grow it, but it was worth it rather than the thought of having to put it on and take it off every night for a year. Besides I'm not sure it would stay on otherwise! It gets pretty hot and sweaty and toasty out there in that big costume.”

Plus it's a great way of getting into the character in this perfect family show: “It really is for all ages, truly a family show. Grandparents love it and children love it. Everyone loves it and it works on so many different levels but actually the humour is really quite sophisticated. It's very clever and I think that's why Roald Dahl has endured for such a long time as stories and as literature. It is just bang on.”

But where do you start with Willy Wonka? “He is extraordinary. He is an enigma. The producers said to me that I would never ever stop discovering new things about him every time I play him. And that's absolutely true. Every single night I find out something else about him. He is so unpredictable. His sense of humour is extraordinary. It is wicked at times. But there is also such depth to him. His intellect is enormous. You don't become Willy Wonka without having the most enormous intelligence.”

But as Gareth sees it, the crux is that it is a moral tale that we are going to enjoy: “Why does he invite the children in? The reason must be that he is looking for an heir because at the end of the show he gives the keys to the factory to Charlie. He doesn't just do that on the spur of the moment. You don't give away the most famous chocolate factory in the world on a whim.

"He doesn't just say ‘Here Charlie, have these!’ I am presuming and the production is presuming that it is all about finding a successor. It's just not something he would do on the spur of the moment and I think that's what makes the story a moral tale. Because how on earth would he believe this rabble of children that he gets in? And all he feels is disappointment. He says’ ‘Don't go into the waterfall.’ He says ‘Don't do this and don't do that’ but they all do.

"And that's the moral. It is a story about such bad parenting. He says ‘Don't chew that gum!’ but they do and that's his disappointment. If you think about it I would certainly do exactly what I'm told to do if it were Willy Wonka telling me. He doesn't take any prisoners. He extraordinary. He's eccentric. He is all sorts of things!”