McFly's played at the Live 8 gig in Tokyo on 2 July

It is the group's fourth UK number one single, following Five Colours In Her Hair, Obviously and their most recent chart-topper All About You.

Former army officer Blunt had been at number one for five weeks with his ballad You're Beautiful.

However, his album, Back To Bedlam, remains at the top of the album chart - for the sixth week in a row.

A surprise new entry, at number five in the singles chart, came from ageing heavy metal rockers Iron Maiden.

Their latest release, The Trooper, came in just behind Pete Doherty's Babyshambles, whose latest single, F*** Forever was a new entry at four.

Daniel Powter's Bad Day moved down one place to number three.