Interviews often verge on the surreal, but this about caps them all. Dale Winton is pouring his heart out about his mum, who committed suicide when he was 21; about why he waited till the age of 47 finally to come out as gay; and whether, at 54, it's too late to knit together his tangled love life. And all the while, a preview of Winton's spangly new Saturday show is playing silently on a TV behind his shoulder. It's hard to focus on soul-searching real Dale with perma-tanned TV Dale grinning alongside him - particularly when your retina is scorched by the image of the celebrity contestant Vanessa Feltz, dressed in a skin-tight silver spandex bodysuit, trying to squeeze herself through a bizarrely shaped hole in an advancing wall that will otherwise push her into some water.

Winton himself seems accustomed to the contradictions of his life. He understands that to some he's a figure of fun; doesn't object when his fellow Gunners fans chant at him: “Dale takes it up the Arsenal”; recognises that he'll win no Nobel prizes for presenting shows such as Touch the Truck, Pets Win Prizes and, the breakthrough that made him an unlikely student icon in the early 1990s, Supermarket Sweep. Yet he takes his work very seriously indeed.

For this new show, a kind of human Tetris that the BBC has adapted from a popular Japanese game show, Winton says he stayed up every night till 3am writing material. It will surprise viewers that a show such as this needs any writing, let alone that the host would do it himself, but Winton insists that this makes the difference between a hit and a flop. And he works as hard on his body as his mind: he lost a stone to be able to wear trendier, more figure-hugging clothes than he does for the National Lottery, and he's long been an advocate of judicious the nip'n'tuck to keep ahead of the young upstarts.

Does his work ethic stem from his mother? Winton suddenly looks vulnerable and startled at the very mention of her name. “I'd say so, yes. My mum came from a very poor background, and she dragged herself up by her own bootstraps.”

Sheree was a glamorous actress with a Bond film on her CV, who had to bring up her only son on her own since he was 9. But, says Winton, "her showbiz career said less about her than the fact that she did her own divorce. I used to come home and she'd be sitting there with books looking for precedent in legal documents from years gone by! And I'm thinking: study. So I've always been a grafter.”

Winton's eyes have pricked with tears, thinking of his late mum. He once said that she disapproved of his homosexuality, wanting her son to find a happy family life. How did Winton break the news to her? “I never did! She heard me on the phone to my then boyfriend, who was very obviously gay, very camp. And it was one phone call too many. She said: ‘Are you on the phone to him again? You do know he's gay, don't you?'

“I thought, ‘Oh God, she doesn't like him being gay, and if you follow it through, she's hateful of me being gay'. This was the question I'd always dreaded, and I didn't know how I was going to handle it. So I actually picked up my suitcase and left home there and then. For a week. She managed to locate me, and we sat down, and she said to me: ‘I will always be your best friend as well as your mother, and I never want you to feel there's something you can't tell me, and I will never judge or discriminate. You are my son, and you don't have a father; you can trust me with anything.'

“She'd obviously spent a lot of time thinking about her words, which were beautiful, magnanimous, and at the same time very welcoming, and inviting an answer. I didn't give the answer. That was the point I should have gone, ‘Mum, I'll tell you I'm gay'. But obviously she knew.

“If I have a regret,” and here his voicefinally cracks, “it's actually that I never sat...although she knew, I...I'm sorry that I never gave her the benefit of that trust. I kind of wished I had, because she died not long after.”

Despite these regrets, it took another quarter of a century for Winton to come out in public, with his autobiography of 2002. Given his on-screen persona - which you could call as camp as Christmas, but only if Christmas were to dress in high heels and a nun's outfit and sing The Sound of Music - it was perhaps hardly a shattering exclusive. So why did he dissemble for so long? “The truth - it's absolutely the truth - is that no one ever asked me. I did countless interviews over the years and I was always waiting for the question. It never came. It became a game, the ambiguity of it all. And I'm not a banner-waving gay guy, because I actually don't believe it's important. People never say ‘vehement heterosexual Michael Parkinson', but it will say ‘camp gay entertainer Graham Norton', or ‘Dale Winton' since I've officially come out.”

Even now, there are people who think he's straight. In part this is because of a bizarre BBC documentary in which Winton “married” the model Nell McAndrew. OK! magazine even carried pictures of the “wedding”. “We did it so well that a neighbour, who is a sir, knocked on my door and said: ‘We are thrilled, absolutely thrilled. Would you like to bring your beautiful wife to dinner one night?' And I thought, oh God, how do I explain this?” Winton did the programme as a satire on reality TV, which he loathes.

A couple of times Winton mentions how much happier and more adjusted he's been in the past five years. “The autobiography probably was more cathartic than I realised. And I decided you don't have to be walking up the red carpet to some God-awful premiere of a film you wished you'd never seen, or go to some party with people who talk bullshit and probably go to the toilet and take drugs, it leaves me cold.” He doesn't even feel the need to consult psychics any more.

And though he's currently single, he's no longer self-destructive in his relationships. He admits inheriting from his mother not just her work ethic, but her habit of choosing “the path of most resistance”: he used to fall in love with unsuitable men that he could never have, men with families leading a double life, even. “That's not me any more,” he says simply.

But regrets, he has a few: particularly that emotional maturity has come so late. “I would love a relationship, but because I have made bad choices in the past, more than once, I'd be very nervous about having anyone move in. I think my age goes against me. I have lived on my own for so long that probably I've become quite selfish. And I can only do monogamy; I've never done one-night stands. People are always telling me to loosen up, go pick up someone, but I can't do it.

“I wish to God,” he says with sudden passion, “that I could shag everything in sight, then I'd have probably had more sex than I ever needed. I am envious of people who could do that. I can't do that. And I'm at the age where I probably now haven't got the chance.”

Perhaps because his father was horrible to him, or perhaps because he left school at 16, Winton still lacks self-confidence, “which is extraordinary considering the job I do”. He never expects people to like him just the way he is, and has a morbid fear of giving offence. He beats himself up so much over getting my name wrong on meeting - “why did I think your name was Day-vid? I don't know, how rude is that? That's the worst thing you can say” - that it reminds me of a Monty Python sketch, the one where a trivial complaint over a dirty fork ends in the chef stabbing himself with it. And in closing, he recounts a terrific anecdote, but then immediately agonises about doing so.

“I was walking past this pub - I've never told this story - and all these hooligans, beer-drinking rough boys, were getting drunk and tanked up. Touch wood I've never had abuse, but this day, I hear this bellow: ‘Poof! F***ing queer!' And I thought, keep on walking. But then I thought, oh give me a break, and I turned round, and this is probably complete insanity, but I walked up, and there were all these guys, and they were all cheering me! I had a load of them on my side.

“So I stood there with a big smile on my face, and I asked [schoolmaster voice]: ‘Who said it? Who said that?' Of course, no one said a word. ‘Who called me a f***ing poof? I want to know.' And so one guy went [sing-song voice]: ‘He did, he did.' And I thought, I'm either going to get kicked in, or there was a part of me that thought, I'm now standing up for what I think is right.

“So I said to him, ‘What did you call me?' [small embarrassed voice]: ‘Er, a f***ing poof.' And I went: ‘You're absolutely right, you win a tenner. Have a drink.' And they loved it! I couldn't bear the thought of that long walk away without turning around and facing it. I had to do that. It was very weird.

“Oh God. I shouldn't have told you that. Does that make me sound bolshie?”

Hole in the Wall starts on BBC One on Saturday at 5.40pm

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