Leona Lewis's cover of Snow Patrol's hit 'Run' has become the fastest-selling digital download ever.

The single was downloaded 69,244 in just two days, making it a certainty for number one this week.

The former X-Factor winner's cover of the track was released on Monday following pressure from a national newspaper.

Lewis, who first performed the song on Jo Wiley's BBC Radio Live lounge last year, sung the track again during a return appearance on The X Factor last month.

The record for the biggest ever digital-only number one is currently held by Estelle and Kanye West's 'American Boy', which sold 51,857 copies in a week.

(by Jason Gregory)