Louis Tomlinson
One Direction singer Louis Tomlinson is returning to The X Factor as a guest mentorDanny Moloshok/Reuters

One Direction star Louis Tomlinson rose to fame alongside bandmates Harry Styles, Liam Payne, Niall Horan and Zayn Malik on The X Factor in 2010, and now, five years on, the singer is returning to the show that made him a household name. He is joining Simon Cowell as The X Factor hits the Judges' Houses stage of the competition this weekend.

Tasked with whittling down his six acts to just three for the live shows, the 56-year-old music mogul has enlisted the help of one of his former protégés to make some of the toughest decisions he will have to make on the show.

In the newly released behind-the-scenes images the 23-year-old singer can be seen meeting hopefuls Max Stone, Ebru, Bupsi, Jennifer Phillips, Kerri-Anne Phillips and Anton Stephans in the South of France. After Cowell complained that he didn't want the Overs category, he appeared to perk up once Tomlinson arrived to judge the hopefuls and he didn't waste time bonding with the contestants over their shared experience.

Louis Tomlinson, Simon Cowell
Louis Tomlinson has joined Simon Cowell for Judges' Houses in FranceITV/Syco/FremantleMedia

One picture proves that the pair are taking their jobs seriously with Tomlinson joining Simon for a pensive gaze out of the window at the French countryside. Another shot sees them deliberating over a contestant.

Back in September, a source claimed that Cowell hoped that Tomlinson's cameo would help the show's ailing viewing figures. An insider told The Sun: "Simon is pulling out the big guns as he is still determined to make this series a huge success. One Direction have always been big ratings winners and Louis is the most outspoken of the band. He won't be afraid to tell people if they're terrible, which Simon loves."

Meanwhile, Cheryl Fernandez-Versini, Nick Grimshaw and Rita Ora have sought help from celebrity friends Jess Glynne, Mark Ronson and Meghan Trainor. Fernandez-Versini took the Groups to Rome, Grimshaw journeyed to the stunning Cotswolds with the Boys and Ora brought the international flavour by taking the Girls to Los Angeles.

In a new twist, this year's contestants won't find out who has progressed to the live shows until this weekend's live broadcast from the Wembley Studios.

The X Factor will return to ITV1 on Saturday 24 October at 8pm.