FORMER One Direction star Louis Tomlinson is reportedly set to become the fourth judge on The X Factor and will sit alongside Robbie Williams, his wife Ayda Field and Simon Cowell.

The singer, whose career started on the show and who helped Cowell at the Judges' Houses in 2015, is poised to sign up for the panel, according to the Daily Mirror.

A source told the newspaper: "Louis is very much a part of the X Factor family.

"He's a close friend of the show and would make a brilliant judge. Simon mentored One Direction and signed them to Syco Records, Now he's looking after Louis' solo career – which is going really well.

"Simon hopes the deal will be done in the next few days."

Tomlinson, 26, found fame on The X Factor as part of One Direction, the most successful band created on the show.

The group finished third in 2010.

Auditions for the latest series, the 15th, start on July 18 at Wembley Arena in London.