4 X-Factor finalists will be axed by their own mentors

The brutal twist will see a quarter of the 16 remaining wannabes sent home as each of the judges dumps one of their own four acts.

And viewers won’t be able to save their favourites — as there will be NO phone vote.

Instead, judges Gary Barlow, Kelly Rowland, Tulisa Contostavlos and Louis Walsh will make their decisions based solely on tomorrow’s live performances.

The singers will then face an agonising 24-hour wait until Sunday night’s show to find out if they have been axed.

A show source said: “This is X Factor with teeth. It’s going to be the biggest drama the show has ever seen. It will be agonising to watch, but compulsive.

“It’s really going to shake things up and bosses are expecting tears from contestants, the judges — and even from viewers.”

The judges have warned finalists about the twist. Take That star Gary, who mentors boys Frankie Cocozza, Craig Colton, Marcus Collins and James Michael, said it would be tough for the acts returning from Judges’ Houses. He said: “It’s one thing singing by the pool but it’s going to feel very different on Saturday.”

N-Dubz star Tulisa — mentoring groups 2 Shoes, Rhythmix, Nu Vibe and The Risk — piled on the pressure as she said the fate of each act rests on their performance tomorrow. She said: “It’s a clean slate.”Kelly — who looks after Amelia Lily, Sophie Habibis, Misha Bryan and Janet Devlin — admitted it will be tough.

She told the girls: “Make the decision hard for us and let us know why you need to stay.”

Louis — with Sami Brookes, Johnny Robinson, Jonjo Kerr and Kitty Brucknell in the Overs category — said: “It’s all to play for.”

Tomorrow’s show, starting at 7.30pm on ITV1, has a UK v US theme, with each act singing a British or American classic.