Hollywood icon Rupert Everett once “did a runner” from a hit BBC show – and now its stars have confirmed the real reason. The Shrek 2 star, who has appeared in everything from My Best Friend’s Wedding to An Ideal Husband, was invited to be part of the Celebrity Apprentice during its 2006 run for Comic Relief.

He was joined by the likes of Piers Morgan, Ross Kemp and Cheryl Cole – but after just a day of filming, he decided to quit the show, with Apprentice winner Tim Campbell stepping in to take his place. At the time, it was reported that Everett couldn’t deal with the constant presence of cameras as he clashed with Piers – but now Lord Sugar and Baroness Brady have revealed his real reason for fleeing.

At the launch of this year’s Christmas edition of the Celebrity Apprentice, which raises money for Children in Need, the pair were asked by press who would be part of their ideal line-up.

Lord Sugar admitted: “Well I think the thing is, it’s very much who’s available. They have their own shows to do, and the quality of the celebrities will very much depend upon who’s in between, in between work. It’s really to do with whether they have a slot in their own schedule – they are busy people.”

Baroness Brady echoed: “I think I echo what Lord Sugar said. You could have a wish list as long as your arm, but we film over a certain period of time. You have to be available, you have to want to give up your time and you have to want to do it.

“It’s not easy. Ask anyone here – it is the hardest working show on TV. When it says 5am, it is five o’clock in the morning and you’re still working at 10 o’clock at night. You’re grafting, you’re contacting people, you’re trying to make sales. It really is tough.”

She added: “Some of the more glamorous names, they might be available – do you remember when we had Rupert Everett? He did a runner! He was like, ‘Where’s my script?’ and I told him, ‘There is no script’. He turned up, he realised it was too tough.”

Everett said at the time: “It is just so different from doing a feature film. I went in with good intentions but I just could not cope with the Big Brother mentality.”

Karren explained: “I think Piers Morgan told him to call his friend Madonna for a donation, he said, ‘You don’t call Madonna, you write her!’ So it’s not just about who’s available, it’s about who will roll up their sleeves and get involved.”

Concerned he’d offended this year’s line-up of talent, Lord Sugar quipped: “I’m very grateful that our celebrities gave up their time to do it – they weren’t the only ones available. There were others! But we have to limit the numbers that we put into the show.”

This year’s festive special includes stars like AJ Odudu, Sarah Hadland, Angela Scanlon and Jake Wood – who will compete to see who can create the best festive biscuit for Children in Need.