Robbie Williams was nervous and sweaty. Whitney Houston lost her dress and struggled to speak. Even the nation's new sweetheart Cheryl Cole has taken a beating from the press. It's fair to say the seasoned performers have not performed brilliantly on this year's X Factor. So it's not surprising that Westlife are a little nervous about their appearance on Sunday night. It's their first gig since getting back together after a year off and they will be showcasing what they have promised is a new sound. 'There is always something a little bit scary about the X Factor stage,' says the band's Mark Feehily. 'It's so huge and you have the judges in front of you. It's like being a teenager at your first audition. 'It's strange - we've performed some massive gigs and huge TV shows but X Factor always makes me a little bit more nervous than anything else we do.

Really, Westlife should have nothing to fear. These were the judges, after all, who gave a standing ovation to Britney Spears after her laugh-out-loud bad performance last season.

Plus Louis Walsh and Simon Cowell will laud this group to the skies whatever happens; one is their manager, the other works for their record label.
Westlife have already appeared more times than anyone else on the hit ITV show - as performers, mentors and even judges. Simon has also ensured the new single What About Now is already recognisable for X Factor fans by featuring it several times as background music on the show.

Simon is said to have loved the new single so much that he even rushed them on to the X Factor this weekend, although they were originally due to appear in a month's time.

'He went berserk and said it's too big a song - I want to get them on the show as soon as possible,' says Kian Egan.

Such is the power of the X Factor that performances from it have already produced the two biggest selling singles of the year from last year's winner Alexandra Burke and judge Cheryl Cole.

In order to get on to the X Factor gold rush there was a hurried change in release schedules with the band putting the finishing touches to their album just a few hours before flying to Iceland on Monday to shoot the video for the song which will now be released on Sunday.