The single features all four of the group singing

The Scottish twins teamed up with comics Peter Kay and Matt Lucas to re-record the song for Comic Relief.

The top three remain unchanged from last week, with Avril Lavigne at two, and Gwen Stefani at three.

Fray's How To Save A Life is at four, pushing Alex Gaudino into fifth with Destination Calabria.

UK TOP FIVE SINGLES 1. (I'm Gonna Be) 500 Miles - The Proclaimers 2. Girlfriend - Avril Lavigne 3. The Sweet Escape - Gwen Stefani 4. How to Save a Life - Fray 5. Destination Calabria - Alex Gaudino Source: Official UK Charts Company

In the album chart, The Kings of Leon shot straight to number one with Because of the Times, followed by Maximo Park's Our Earthly Pleasures in second place.

Last week's highest new entry in the album charts, Rocket Man - The Definitive Hits by Elton John slipped from two to six.

Re-formed boy band Take That took a tumble in both charts, as their hit single Shine fell seven places to number 15, and their album, Beautiful World, fell from top spot to number three.

It was better news for Sheffield four-piece the Arctic Monkeys, whose new track Brianstorm entered the chart at number 11.

The band made it available for download ahead of its physical release on 16 April.

Their new album Favourite Worst Nightmare is out on 23 April.