Millions of people were tonight expected to tune in for an unprecedented cross-channel TV broadcast of the new Band Aid video.
It is being broadcast for the first time on all five terrestrial networks as well as more than 20 cable and satellite channels.
Organisers said the “emotional” video featured images from the recording of the charity single as well as news pictures from Africa.
A spokeswoman said: “It is something completely unprecedented. I have never known even for a royal occasion to be shown on all channels like that.”
All the channels are due to show the new video at 5.55pm tonight.
The spokeswoman added: “What we have got to make sure is that as many people as possible buy the single and I can’t think of a better way of doing that.”
Pop queen Madonna is due to introduce the broadcast by reminding viewers that “none of us can forget” the problems facing the Third World.
The single updates 1984’s Do They Know It’s Christmas which was released to raise money for the famine in Ethiopia with a line-up brought together by Geldof.
Geldof has now brought together a host of figures from today’s pop world to record an up-to-date version of the track.
U2 frontman Bono has won the battle to belt out “And Tonight Thank God it’s Them Instead of You” as he did two decades ago.
But Coldplay’s Chris Martin, singers Dido and Robbie Williams have the opening lines of the song.
The Sugababes, Fran Healy from Travis, Justin Hawkins from The Darkness, Will Young, Jamelia and Ms Dynamite are also on board.
The new single is due to hit the shops in less than a fortnight and tipped to be the seasonal Number One.
The single is also available to download from today, but bookmakers have lengthened the odds on the track’s long-term success following lukewarm reviews.
Meanwhile, it is also being launched as a charity ringtone on Monday, a week before the single reaches the shops, with proceeds going to the Band Aid trust.
Mycokemusic.com said it was putting the track on its website today with all profits donated to charity.