In a cramped dressing room beneath the Playhouse theatre, in London, the familiar features of Graham Norton are slowly being transformed. Back goes the hair, secured by a band. On goes the slap, as a make-up artist, fluttering above the television presenter, sets about turning him into Albin, the cross-dressing star turn in the hit musical La Cage aux folles. With just three days to go before his debut in the role, in which he replaces Douglas Hodge, the atmosphere is fraught. Arrayed above and beside the mirror Norton stares anxiously into are notes and good-luck cards to Hodge, whose performance was regarded by many as one of the greatest in recent musical-theatre memory.

Norton trained at the Central School of Speech and Drama, in London, but long ago abandoned thoughts of a career as a serious actor and began his steady ascent to the light-entertainment summit by appearing on the stand-up circuit. With an outsiders-not-welcome run-through about to begin, the 45-year-old sits looking exhausted and, frankly, terrified in front of the mirror’s multiple light bulbs.

“I promised myself I’d be in bed by 10 last night,” he says. “And I made it by 11, fell asleep, then woke up thinking, ‘Well, it’s probably early, but at least I’ve had some sleep.’ I looked at the clock and it said 12.30am.” He doesn’t reveal if he managed to go back to sleep, but his face suggests it may have been a struggle.

His decision to appear in La Cage aux folles is an act of recklessness of the type his career has been sorely lacking of late, a truth he seems to acknowledge when, after describing himself as “fantastically frightened”, he continues: “I haven’t felt like that in years — probably not since my first couple of stand-up gigs. And it’s quite nice to feel like that.” Then, in an aside that reminds you just how plain naughty he can still be, Norton adds: “It’s like self-harming, I suppose: you feel alive.”

Not that you’d get him to admit that his television career has grown steadily safer the higher his ratings (and his pay) have climbed. Norton is adept at deflection, either going into an “I’ll hold my hand up to that” routine or simply avoiding the question. He does both, it has to be said, charmingly, and the old mischief still twinkles in his eyes as he does so. The accusations that are most commonly levelled against him — that he’s overpaid; that he demeans himself by overdoing the camp; that the BBC, far from accommodating his once dangerous and risky talent, has instead defanged it for the “Saturday night on the sofa” audience — are ones he is practised at dealing with.

That doesn’t mean the mask of serenity can’t sometimes slip. While addressing the questions of “acceptable camp” (the same tag once applied to Larry Grayson, John Inman and Danny La Rue) and cleaning up his act for the mainstream, something malfunctions, and for a moment he looks as if he’s going to bare his teeth. Perhaps it was my phrase “playing to the gallery”. “The audience is in the gallery,” he says, speaking slowly and suddenly sounding exasperated. “I’m there to please the audience, and if I’m not doing that, what’s the point of it?”

But he recovers, then comes out with something much more revealing. “That kind of Uncle Tom criticism, I became aware of that when I was doing stand-up. I remember a couple of times on stage thinking, ‘This isn’t very nice. This is very “Dance, monkey, dance”.’ It didn’t feel nice, it felt nasty. After that, I made a deliberate promise in my head not to go out and do that. There have been times on the chat show, particularly on Channel 4, when the scriptwriters have put in another cock-and-bum joke, and you’re like, ‘Really? Do I have to do another one?’ ”

On the subject of his BBC salary — a reported £5m for a three-year contract — Norton is upfront. “I can neither defend nor explain the money I’m paid,” he says. “It’s baffling to me, but, equally, if the market forces have decided that I’m worth that — and I’m not saying I am, I’ve no idea — but if they have decided that, then of course I’m going to take it. Who wouldn’t?”

Presumably, he sees why people might object to such levels of remuneration. “Compared to the vast majority of people, I’m ridiculously well paid, and I’m sure people resent that. I would, too.” Still, that payday, big as it was, was as nothing compared to the cheque handed to Jonathan Ross. “Oh, the good thing about Jonathan Ross’s salary is that it took the heat off everyone else,” Norton says, looking much more cheerful. “And that’s what really did him in. If two breakfast DJs from BBC Norwich had rung Andrew Sachs, they’d still have their breakfast show and nobody would really care.”

Has he noticed a change in attitudes at the BBC since the Ross/Brand scandal broke — a creeping censorship, as some detect? “You’re aware of the mood,” he replies. “But at the same time, I just get on and do my job. You can’t do your job if you’re desperately trying to second-guess things the whole time. What nobody says is, ‘Look, the BBC has four TV stations, seven or eight radio stations, 24 hours a day, 365 days a year — it was a blip.’ They police the output incredibly rigorously. On the chat show, the script gets shown to the lawyers; lawyers and executives come to the recording, and they go to the edit. The public are very protected from me.”

Perhaps stepping into Wogan’s shoes as presenter of the Eurovision Song Contest will see Norton breach those taste barriers. Does he anticipate becoming annoyed, as Wogan was, by the block voting, and laying about him as a consequence? “I can’t imagine being that upset by it,” he laughs. “It is a singing competition, you know. We’re not looking for world peace here.” And once again, his eyes twinkle with mischief, which surely bodes well.

When Norton was poached by the Beeb from Channel 4, there was a perception that the corporation was floundering around trying to find a suitable vehicle for him. It’s a perception he has, arguably, never quite shaken off, no matter the success of shows such as How Do You Solve a Problem Like Maria?, Any Dream Will Do and I’d Do Anything. The sheer weirdness of his early television and radio appearances, the sense that at any moment he could veer wildly off piste, has largely gone. Yes, his BBC chat show, Graham Norton’s Bigger Picture, can still take the breath away. But there is something inescapably grim about seeing Norton, scrubbed clean, eager to please, cosying up to Andrew Lloyd Webber on shows that seem like little more than handy promotional pushes for the latter’s West End productions.

Now, though, Norton has his own West End production to worry about, which will introduce us to a side of him none of us has the slightest experience of. Nor, more to the point, has he. He’s been having singing lessons, but you sense it’s going to involve a little more than that. “It will never be a great vocal performance,” he laughs, “but what’s good about this musical, particularly my character’s songs, is that they come completely out of the plot and the action. You’re not there to twitter like the birds in the trees.” He has cut back on drinking and is trying to get some early nights. “There are all these kids in the show,” he says. “They’re, like, 20. They can go out every night and have a bit of a lie-in, then come in the next day and still sing and dance. I can’t do that any more. Someone must put me in a car and send me away at a certain hour.”

I don’t for a minute think he’s taking the part because those “serious actor” ambitions still burn within him (though the leading role in a musical forged in the first dawn of Aids and addressing issues of redemption and sexual identity is serious enough). I suspect he is doing it as a way of hurtling, pell-mell, out of the multimillion-pound comfort zone he finds himself in. “The reason I’m going back to theatre is this show, and this part in this show,” he says. “I saw the original Broadway production on tour in 1984, and I remember thinking, ‘When I’m old enough, I’d love to play that part.’ ”

Well, now he is. As Albin sings in the showstopping I Am What I Am: “So, come take a look / Give me the hook, or the ovation.” Which will it be? We shall see. And so, of course, will he.

La Cage aux folles, Playhouse, London WC2

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