Gary Barlow thinks Geri Halliwell will be a "crazy" judge on 'The X Factor'.

The Spice Girls star is joining Gary, Tulisa Contostavlos and Louis Walsh on the panel of the ITV1 talent show as a guest judge in Liverpool this week, and he admits he is looking forward to working with her.

He told the Daily Star newspaper: "I'm feeling good about 'The X Factor'. The guest judge thing is great. We've got Geri on Thursday so it's going to be crazy."

It is believed should Geri do well at the audition she may be asked to sign up for the full series, despite not going down well with the public when she appeared as a guest judge in 2010.

Meanwhile, comedian Peter Kay is also set for an appearance at Liverpool's Echo Arena for the show after asking producers if he could be a warm-up act.

A source told The Sun newspaper: "Peter loves reality TV. He is also good mates with Gary and wanted to have a taste of it. He rang up the producers on the show and asked to be part of the team in Liverpool.

"He'll do a few gags and he may even throw in a Take That number."