A contestant from the upcoming Celebrity Traitors has admitted that the experience was "brutal". They opened up about the Traitors spin-off following the line-up being confirmed after production began on the reality TV show. Clare Balding , 54, said she found the BBC show "challenging" as it meant her friendships with co-stars like former Olympic diver Tom Daley went "out the window". They are among the 19 celebrities who have taken part in the first series. Speaking candidly at the Goodwoof event while promoting her new novel Pastures New, Clare admitted: "It is so intense, and you get completely obsessed with the game." Teasing friendships don't always hold up amidst the gameplay, she said: "Obviously, I knew quite a lot of them before I went in, but the friendships you had before go out the window!" The broadcaster continued: "That, for me, is very challenging because I like to be friends with everybody! It's brutal, but I think I'm glad I did it. It will make good television, and there are some really strong moments." Clare and other celebrities, like presenter Stephen Fry , actor Celia Imrie , comedian Nick Mohammed and singer Charlotte Church , will be seen playing the beloved game at Ardross Castle in the Scottish Highlands. On the show, hosted by Claudia Winkleman , they will compete to win a cash prize of up to £100,000 for a charity of their choice. Praising Nick, she revealed: "There are some people who are so clever. I mean, Nick Mohammed from Ted Lasso , he can solve problems and puzzles in like four and a half seconds. He's amazing." Crufts presenter Clare also shared her delight over spending time with other contestants during the filming of Celebrity Traitors. She gushed: "It was lovely to get more time to hang out with people like Stephen Fry, Celia Imrie, Charlotte Church, who's an absolute superstar, and a really cool young singer called Cat Burns - I would not have met her and Ruth Cobb, who's an actress, in any other situation, and I loved that. Yeah, it was great fun." The line-up for Celebrity Traitors was announced earlier this month. Clare, Tom, Stephen, Celia, Charlotte, Cat and Ruth are among the 19 celebrities who are involved in the spin-off, which is set to be broadcast by the BBC later this year. Comedian Alan Carr , filmmaker David Olusoga and former rugby union player Joe Marler will also compete. Other celebrities in the line-up for the show include comedian Joe Wilkinson, presenters Jonathan Ross and Kate Garraway . They will compete against the likes of comedian Lucy Beaumont and actor Mark Bonnar , too. Content creator Niko Omilana, singer-songwriter Paloma Faith and EastEnders star Tameka Empson are also in the line-up. Host Claudia commented: "We're incredibly lucky these brilliant people have said yes. I'd love to say we'll take it easy on them and they'll just wander round the castle and eat toast for a couple of weeks but that would be a lie." Celebrity Traitors is scheduled to air in the autumn on BBC One and BBC iPlayer. Like this story? For more of the latest showbiz news and gossip, follow Mirror Celebs on TikTok , Snapchat , Instagram , Twitter , Facebook , YouTube and Threads .