One Direction have revealed that they can no longer stomach watching the show that propelled them into the spotlight because even the theme music makes them nervous. 

Speaking to the Daily Star newspaper, the 'What Makes You Beautiful' stars explained that sitting in front of the television while The X Factor is on fills them with fear. Member Liam Payne said:

"We can’t watch the show in the same way now. The music makes me really nervous, as soon as I hear that theme tune I feel sick. It takes me backstage again and waiting to perform live.”

Talking about the possibility of being invited back to perform their new single on the show, the group - who recently announced details of their debut UK headlining tour - added that it's a decision that needs to be made by music mogul Simon Cowell:

"We need an invite from Uncle Si. He makes the last decision on everything. He’s so busy in America he could easily have left somebody else to do it but he’s been hands on. He loves the album, he’s like a proud dad.”

Watch behind-the-scenes footage from the boys' recent promotional photoshoot below: