One Direction have been given the opening lines of Band Aid 30's 'Do They Know It's Christmas Time?'.

The star-studded charity single - which will raise money for the fight against the Ebola virus - was unveiled for the first time last night (16.11.14) on 'The X Factor' after being completed at 4.20am and it is believed the acts involved didn't know which lines they had been given until the ''rough'' edit aired.

The 'Steal My Girl' group were thrilled to be asked to be a part of the project, with Liam Payne telling The Sun newspaper: ''We've seen it every year on the telly since we were kids.

''And now thinking that we'll be old and grey one day and we'll just pop up. It's amazing.''

The video for the single incorporates footage of the celebrities - including Ed Sheeran, Rita Ora, Sam Smith, Coldplay's Chris Martin, U2's Bono and Paloma Faith - recording the track with harrowing footage of West African victims of the virus, and organiser Bob Geldof warned on 'The X Factor' that it was ''not suited to an entertainment show''.

He said: ''Thanks Simon [Cowell] for allowing us to do this, this is hardcore, to allow X factor nation to do this, it is an enormous production, this thing [Ebola] could arrive here on a plane any time.

''This is the most anti-human disease but we can stop it, and we will stop it, and we will support those immensely brave NHS doctors and soldiers who have volunteered, and the government who are leading the world on this.''

With the track now available for download, the Boomtown Rats frontman urged people to buy as many copies as possible.

He added: ''At 8am tomorrow morning, for the first time this is about us, buy this thing, buy five by ten, it's a great track, we wanted to show you the context of how this was done only yesterday.''

Other stars appearing on the track include Seal, Elbow, Emeli Sande, Sinead O'connor, Bastille and Olly Murs, with the 'Troublemaker' singer describing the recording process as ''amazing''.

He said: ''It was an amazing experience to be part of that, its 30 years ago since 1984, it was amazing to be a part of it, it was brilliant.''

Bob and Midge Ure have reworked some of the lyrics for the track, with the most famous line from the original, ''Tonight thank God it's them instead of you'' - which was performed by Bono on both the 1984 and 2004 versions - changed to ''Well tonight we're reaching out and touching you.''

The revised line is still sang by the U2 frontman.