Celebrity SAS: Who Dares Wins was spun into turmoil as three of its celebrities quit within just days of filming.
Among those to step away from the gruelling Channel 4 show were Ulrika Jonsson, Vicky Pattison and Jake Quickenden.
Appearing on Good Morning Britain today, former Special Forces soldier Jason Fox opened up about the simple reason why they quit.
Host Charlotte Hawkins probed him: "The celebrity version [of SAS: Who Dares Wins] is underway, isn't it? But we've understood that some people have left already, which isn't sounding good."
Co-star Kate Garraway added: "Yeah - Jake Quickenden, Vicky Pattison and Ulrika Jonsson."
Charlotte asked: "Were they thinking that it was a bit too tough for them? What can you tell us about that?"
He replied: "Without ruining it, I can't say too much. But yeah, a few people turned up not quite understanding what it was they were doing."
"Might have taken on more than they signed up for," Charlotte quipped.
Kate added: "There's no messing about on that show, is there?"
"No, there's not," Jason said with a smile. "It's quite tough."
*Good Morning Britain airs weekdays at 6am on ITV
