The Hillsborough charity single has nudged ahead of X Factor winner James Arthur in the race for the Christmas number one.
Arthur took a surprise early lead yesterday in a tight battle for the festive top spot by a margin of just 3,000 copies.
However, the star-studded Hillsborough track, recorded under the name of The Justice Collective, now has the edge with a 3,400 lead.
The single - a cover of The Hollies hit "He Ain't Heavy, He's My Brother" - features names such as Robbie Williams and Sir Paul McCartney.
It has now sold around 109,700 copies, to Arthur's 106,300, according to figures from the Official Charts Company.
In a celebrated battle for the top of the charts in 2009 Rage Against The Machine's "Killing In The Name" and Joe McElderry's "The Climb" were in a tight race but the two records were at least 8,000 sales apart during the week and the rock act finally finished 52,000 copies ahead.
Official Charts Company managing director Martin Talbot said: "This really is the closest number one battle we can remember. There is a long way to go yet - but this one looks like going down to the wire."
The number one will be revealed during the chart countdown on Sunday on Radio 1.
Gennaro Castaldo, a spokesman for music retailer HMV, said: "The race remains a close one, but with just a few days to go the momentum now appears to be firmly with The Justice Collective.
"Not surprisingly we're seeing particularly phenomenal demand in Liverpool and the North West, but sales are pretty good elsewhere, which show that the campaign is connecting with people around the rest of the country as well."