A week before Comic Relief night, a host of celebrities join Graham to celebrate the 30th anniversary of the iconic fundraiser. With guests Cheryl Fernandez-Versini, Jennifer Saunders, David Walliams, Jack Dee and Johnny Vegas.

Jennifer, sporting a Comic Relief onesie, glasses and fake eyebrows, talks about 30 years of being involved in the fund raising, "To be honest, when Dawn (French) and I started we thought it was a one-off gig. Comic Relief is one of the few places where you can actually do anything you want; they say, 'What do you want to do? You can do that.' And off you go. It's been like a dream."

On once playing a 'Sugar Lump' alongside Spice Girls in a sketch, she says, "They were up for it, but I don't know how funny Victoria thought it was. It was the best fun ever."

Talking about being in The Great Comic Relief Bake Off final on Friday 13th March, and asked if the bar was set quite low, she says, "No, but Lulu had never turned an oven on and Joanna Lumley had never cooked anything. I think I was the only one that had ever cooked before." Asked if that meant she won by default, she says jokingly, "No, I won because I am brilliant," adding, "Vodka was involved in the making of my cake and in the making of the programme. It was edited very, very kindly because we got fairly hysterical by the end."

Jack interjects, "I was asked to do the Bake Off and I wrote back as a joke saying, 'I don't want to do it because I find Mary Berry very, very aggressive; I don't like her at all.' And they wrote back, 'She's actually very nice but if you don't want to do it...' I was joking!"

David, who has raised a phenomenal amount for Comic Relief, dispels the rumour that he and Cheryl were once nearly an item, "When Girls Aloud came along I met Louis Walsh and asked him if any of the girls were single and he said he would ask. I thought he would do that discreetly, but he called a meeting of all of them and asked, 'Do any of you want to go out with David Walliams?' it was a 'No!' And that was the end of that."

Talking about his and Matt Lucas's Little Britain sketch with Elton John in 2009, he says, "He didn't know what we would ask. We only knew we wanted him to say he was 'the only gay in the village' at the end. It was amazing. He has a good sense of humour and the great thing with Comic Relief is that no one can really say, 'No.'"

Revealing that this year he will appear in a sketch with Stephen Hawking, David says, "I don't know how he got involved but he knew the show (Little Britain) and he is a comedy fan. I was chuffed he agreed and I loved getting script notes and I thought, 'How often do you get script notes from a genius like that.' I was blown away and was actually very moved by the end of it; I felt like crying because I was so grateful he'd done it."

Talking about his new book, The Queen's Orang-Utan, from which all the profits will go to Comic Relief, he says, "I was talking about it in a school in Manchester and asked if there were any questions. One child asked what I would do if I had £1,000 and another asked what I would do if my phone was stolen at an airport. It was really sweet and so random."

On meeting The Queen he says, "I really love her and was so thrilled to meet her. You're not allowed to ask The Queen a question so I said, 'Thank you so much for coming.' It was the Royal Variety Performance - she had to come!"

Cheryl reveals her own royal faux pas, "I had a meeting with Prince Charles and I had been given so many instructions about what and what not to say and do that I got really nervous. He was telling me how much he loved ballroom dancing with Camilla and referenced a movie and I said, 'They don't make them like that anymore do they Charlie?" There were inward gasps of breath from my PA and his aides but he carried on as though nothing had happened."

Claiming to be sporting her shorter, redder hairstyle especially for the charity she says, "I've cut it and I've dyed it red in aid of Comic Relief."

Talking about how the charity changed her life, she says, "I did Comic Relief Celebrity Apprentice in 2007 and no one had the nerve to call Simon Cowell other than me, which I did on camera asking for money. I left him a voicemail saying, 'It's Cheryl and I want some money from you. You have half an hour to call me back and I would like between one and ten thousand pounds.' I didn't think he would turn up but he did and gave us £25k. Ever since then he says he admired my tenacity. And that was the beginning of our working relationship."

Revealing she wasn't best prepared when she made the summit of Kilimanjaro in 2009, Cheryl says, "It was grim. I didn't do as much training as I should have. I was really bad and I don't know how I reached the summit. I got my mum to break in my shoes and I had a cross trainer that had a setting that said 'Kilimanjaro' and I'd do 45 minutes of that. I was kind of expecting it to be a pleasant walk, which I don't mind, but it wasn't. I was kidding myself and I don't now how I did it."

Johnny interjects, "We watched that film and my wife said, 'You could do that, you could climb Kilimanjaro,' there was a pause and she then added, 'If you just changed everything you are!'"

Jack, talking about his contribution to Comic Relief in the past, jokes, "I once stood on a pole for six hours. I looked like Nelson. No one remembers and no one cared. I didn't understand; it was pointless. It wasn't even dangerous because I was welded to the thing. I think they put me up there to get me out of the way and I had to pee into a funnel - I don't know where it went. Perhaps that was a whole other challenge!"

And on his famous appearance on, and escape from, the first ever Celebrity Big Brother, he says with his tongue firmly in his cheek, "It's been an enduring nightmare throughout my career! I'd not watched the show so didn't know what to expect but as it was for charity I expected an easy ride. I escaped in sheer desperation." Asked why he came back he says, "I hadn't paid any attention on the way to the place and I didn't know where I was. I was in Stratford East at three in the morning and I thought, 'If this is what the outside world is all about, I'm going back!'"

Johnny, revealing that this year he will be performing in a One Direction tribute band - 'No Direction' - live at the London Palladium on the Red Nose Day night of TV, Friday 13th March, says "I'm going to be one of the singers - I don't know which one but he has a red hoodie. I'm a Leonard Cohen sort of guy and One Direction doesn't really go with that. I'm going to learn the song, sing it and to dance to it."

Asked whether he would be willing to do a more physical challenge to raise money, he says, "I wouldn't mind having a go at American wrestling. I'd like to wear some Spandex and fight Hulk Hogan - I'd really go for it, though we might struggle with the insurance - I haven't been offered any of the big challenges as I get out of breath looking for the stairs!"

And finally, Graham pulls the lever on more foolhardy audience members brave enough to sit in the Red Chair. This week they are judged on their best jokes, with Graham and his guest proving a tough audience to please.