He is being fitted for a wig, sitting on a high chair before a dressing table. From this distance he appears to be completely naked. “Let’s take you over to say hello,” the publicist suggests, and, taking a deep breath, I duly follow in her wake, smiling and pointedly making eye contact with the vividly painted and powdered television star in that via-the-mirror way in which you communicate with hairdressers or taxi drivers. “Delighted,” says Norton, turning round in preparation for climbing down from his perch. (“Whatever you do, don’t look down,” I tell myself.) The scrape of high heels on bare boards as he does so is at least partially reassuring, and a subsequent glance floorwards finds him also to be wearing American Tan tights over what appear to be incontinence pants. “A few more minutes and then [here he shoots me a significant look] I’m all yours.”

To borrow the title of one of the comedian/presenter’s past Channel 4 chat shows, that delivery is So Graham Norton. No one filters the same fruity mix of sharp wit and innuendo through a persona of campness as he does. Like Frankie Howerd and Kenneth Williams before him, he is a knowing commentator on the antics of others while remaining non-sexual and, hence, non-threatening himself. It’s a neat trick, one on which until recently he built his whole career. Then came a multimillion-pound contract with the BBC, not to titter over smut late at night with visiting celebs, but to front primetime light entertainment fare such as How Do You Solve a Problem Like Maria?, Any Dream Will Do and I’d Do Anything, in which unknowns vied to be cast in West End shows. Newly mainstream as a result, it’s therefore a surprise to find him venturing sequin-clad into the world of theatre, starring as Albin in the musical La Cage aux Folles.

This is not Norton’s first experience of cross-dressing. The Guinness salesman’s son from Bandon, County Cork (a town of 5,000, its previous best-known inhabitant was a Victorian novelist, Margaret Wolfe Hungerford, who died of typhoid there in 1897), used to put on his sister’s clothes when just a tiny tot, “because they were prettier”, he once explained. “I was just trying to brighten up a dull wardrobe.” And then, in the early days of his post-drama-school career as a stand-up, there was an appearance at the Edinburgh Fringe in a one-man show titled The Mother Teresa of Calcutta Grand Farewell Tour. “But that was just me and a few tea towels,” he says. “I’ve never before done actual drag and it’s quite a shock, I can tell you. You look at yourself as the slap goes on and you think, ‘It’s me. It’s me. It’s still me.’ Then comes a tipping point – the lips? The wig? – and suddenly it’s, ‘Oh my God! Who is that?’ ”

It was the experience of working on those search-for-a-star BBC TV shows that softened Norton up to the idea and made him decide, “Actually, musical theatre isn’t as freaky as I thought. You work with people who are entirely normal in every other respect but who also perform in that world and you find yourself thinking, ‘Maybe I could do it too…’ ” His first step was to begin vocal training with a renowned coach, Mary Hammond: “Let’s name and shame her, ’cos it’s her fault too if I bomb.” Then the casting director David Grindrod asked what kind of production Norton would be interested in being considered for. “And there was only one, this one. I’d been along to see it at the Chocolate Factory with Douglas Hodge as Albin and like everyone had absolutely loved it – the reviews have been amazing. When I said it, I had no idea a West End transfer was on the cards.” Kismet, in other words.

La Cage aux Folles is a warm-hearted, uplifting, gently educative farce originally published in 1973 by the French writer Jean Poiret and later developed into a trilogy of French-Italian films, a stage musical and, in 1996 and under the title The Birdcage, a Hollywood vehicle for Robin Williams. It tells of a gay couple, Georges, the owner of a nightclub showcasing drag acts, and Albin, its star attraction, and all that befalls them when Georges’s son from a one-night stand brings his fiancée’s conservative parents to visit.

“The role of Albin [which Norton will assume in January] is a showcase for a fun, camp extrovert, and while Graham is many things, chief among them are certainly fun, camp and extrovert,” says producer David Babani, who has seen the show transfer from the acclaimed Menier Chocolate Factory, South London, to the Playhouse Theatre in the West End. “He’s absolutely perfect. I genuinely can’t wait to see his performance.”

When Norton presents himself for interview at the photo studio wearing a T-shirt, trainers and jeans, his face newly scrubbed, I remark how thrilled the company appears to be that he has come on board. In response, he rolls his eyes theatrically. “Oh, they’re all thrilled now,” he declaims, giving the trademark glug-glug-glug Norton laugh, “but just wait until we start rehearsals. I am almost literally s****ing myself. By the time opening night comes round, there may be nothing almost about it. Luckily, I have my special pants in case of mishap [in fact, he tells me that the passion killers he was wearing earlier are special drag-artist ones, padded at the cheek and hips to give a more womanly silhouette beneath a sequined gown]. I spend most of my working life in a very comfortable, well-supported place and this is so out of that zone. If I’m honest, it’s scaring the bejaysus out of me.

“Truly, honestly, I have no ambition to inhabit this world permanently. Theatregoers can relax, I promise. I’ll do this one thing and then I’ll p*** off again. And that’s if I even survive the run [he is contracted initially for three months]. Everyone loves everything about the production exactly as it is, and the last thing I want to do is come in and kill the beautiful baby.”

None of which explains why La Cage so resonated with Norton that he was prepared to risk a critical drubbing after Douglas Hodge received such acclaim for his performance in the role. (“I can’t help but think that to all those reviewers who’ve hated me for years on TV, I’m going to represent a late Christmas present.”) To understand that, you need to be his 20-year-old self, an escapee from rural Ireland to a hippy commune in San Francisco, struggling to define his identity, sexual and otherwise, and seeing the show there on its first direct-from-Broadway national tour.

One of the four numbers that the character of Albin performs solo is I Am What I Am. “Which these days is a hackneyed anthem drag queens and fag hags everywhere sing at the drop of a hat. But back when I first heard it all those years ago, it was incredibly moving, both in terms of where I was in my own life and where gay culture was – a whole generation about to be decimated by Aids. The idea that what people laugh at and deride you for is also what makes you special is definitely something I can relate to. As a kid, I was very much afraid of my own campness. In terms of self-acceptance as a young man it was my biggest hurdle, and that’s why the song’s lyric and attitude spoke to me so powerfully. Of course, age and experience alters your perspective. Now, at 45, the number that gets me the most is The Best of Times. Seize the moment! None of us knows how much longer we’ve got.”

Norton says that as a self-consciously different child growing up in the small-town Ireland of the Seventies, the only visible gay role models were TV personalities like Larry Grayson and John Inman, “and you really, really didn’t want to be that person”. And when in adult life he began to meet actual examples from that heightened genre gay personae, he felt a similar unease. “I mean, men who’ve not just wholly accepted it. Dear God, they’ve lovingly embraced it. They’ve thrown petrol on the bonfire of their own campness. You know, the constant eye-rolling, the calling everyone ‘she’? And that puzzles me, too. I think, ‘What life choice was this for you? What made you want to be this particular person?’ ” So, on a one to ten of camp, where would he place himself? “Hmmn. I used to think I was an eight-and-a-half, but now that I’ve stepped into this musical world I realise I’m comparatively butch. Reviewers may even say I’m too manly to convince in the role!”

Had he the choice, would Norton be a different man, perhaps one who is more toned down and “straight-acting”? My use of that term from the homosexual lexicon makes him snort with amusement. “So funny, some of the men who apply it to themselves. You hear them say, ‘No one at work knows…’ Oh really? And who is your employer? The Helen Keller Institute? No, I’d say I’m very happy in my own skin these days. Again, I think it’s an age thing. There are very few pros to getting older but that’s definitely one, the not longing to be someone else. You look at young people still trying to ‘find’ themselves and you think, ‘Sheesh, I’m so glad I’m not doing that any more.’ If I were to wish to be anything, it’d be younger and prettier, as would almost anyone else. I’d wish to be the sort of gay man I actually was 20 years ago but didn’t ever realise at the time.”

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