James Arthur is the fastest-selling X Factor winner in the show's history.

The singer's winner's single 'Impossible' has sold over 187,000 downloads during its first 24 hours on sale, since he was crowded champion on Sunday evening (December 9).

The first-day sales figures have been released ahead of the track's physical release on Wednesday (December 12), which will help boost sales further, reports the The Official Charts Company.

Alexandra Burke's 'Hallelujah' was the previous fastest-selling winner's track, after it sold 147,000 copies during its first 24 hours on sale back in 2008.

Matt Cardle...