Written by Take That founder Gary Barlow and composer Andrew Lloyd Webber, "Sing" is a collaboration between artists from across the Commonwealth, the group of nations comprised mainly of former British colonies.
Barlow`s album of patriotic tunes, including "Sing" and the British national anthem "God Save the Queen", spent a second week at the top of the album chart.
Prince Harry, son of heir-to-the-throne Prince Charles and the late Princess Diana, played the tambourine on "Sing".
Around 200 people performed the song at a Diamond Jubilee concert in front of the queen`s London palace on Monday.
Australia`s Sydney Symphony Orchestra recorded part of the music at the Sydney Opera House, while a Rastafarian priest from Jamaica provided some of the drumming.
Other performers included a choir made up of wives of British servicemen and the Slum Drummers, a group of street children from Kenya whose instruments are made from scrap they have salvaged.
The Official Charts Company, which compiles the weekly rundown, said the song had outsold its nearest rival by three to one since entering the chart at number 11 last week.
American rapper Flo Rida entered the chart at number two with his new track "Whistle", ahead of "We are Young" by U.S. band Fun and singer Janelle Monae. (*)