The finalists go head to head as they sing live in a bid to win this year's competition and bag a life-changing recording contract. Also battling it out are judges Simon Cowell, Louis Walsh, Dannii Minogue and Cheryl Cole, while host Dermot O'Leary is on hand to keep the warring parties at bay. Plus there will be performances by some amazing international guest stars. The voting lines open tonight as the countdown starts - tomorrow night, one act will win the X Factor.