Dermot O'Leary hosts the third week of the singing contest's live shows, with the remaining acts keen to impress the judges as well as the viewers who will be casting votes for their favourite - with tomorrow night's results show revealing which acts have proved a hit and who will be leaving the contest this week. This year, Simon Cowell is in charge of the Girls, Louis Tomlinson has the Boys, Ayda Williams has the Overs, and Robbie Williams puts his Take That background to good use in coaching the Groups. (thetvdb.com)