More than 100 artists are believed to be taking part, including comedian Peter Kay. The record label claims the line-up is ‘the greatest supergroup of all time'.
The consultancy, which was founded two months ago by former Outside Organisation staffer Stuart Bell and Polydor Records' head of press Richard Dawes, will work closely with the record label, Chapman Entertainment and the BBC to help promote the top-secret single.
A video of the song will be broadcast for the first time on the fundraising appeal programme when it airs on 20 November.
Meanwhile, 19 Entertainment has asked Dawbell to handle Emma Bunton's personal public relations.
Recent media reports have suggested she and the other members of The Spice Girls are planning to launch a reality TV show to find actors to play themselves in a West End theatre show.
19 Entertainment's Simon Fuller is reportedly working with the band on the idea. Dawbell's client list inc-ludes Sir Paul McCartney, Leona Lewis, Take That, Ronan Keating and Detroit Social Club.