Published Wednesday, 16 December 2009
Rage Against The Machine widened the gap over X Factor winner Joe McElderry in the race, building up a lead of more than 60,000 sales.
Ladbrokes said it was the first time since X Factor started in 2004 that the winner has not led the way in the betting.
Spokesman Nick Weinberg said: "Joe's loss of favouritism is a landmark moment in Christmas number one betting.
"It was inconceivable just a few days ago, but the gamble on Rage Against The Machine has taken us completely by surprise.
"For so long the battle for festive supremacy has been a procession for the X Factor - not anymore."
The rock release, seen as an anti-X Factor protest vote by music fans, edged ahead of the show's winner on Tuesday - and new figures show the lead is growing.
Surprise contenders Rage Against The Machine (RATM) praised the internet campaign which has driven their sales and declared: "Let the people decide."
The band's track Killing In The Name - originally released in 1992 - and McElderry's song The Climb together account for nearly 300,000 sales so far this week.
In South Shields town centre thousands queued outside HMV in the hope of catching a glimpse of the X Factor winner.
Only 500 were allowed into the music store to get a signed Joe McElderry single.
Until now the X Factor track had only been available on download and it is thought many people will buy the CD as a stocking filler.
The Christmas sales can buck the overall trend for CDs making up less than 2% of singles sales.
Earlier William Hill's spokesman Rupert Adams said: "It is a straight fight between the X Factor and Rage Against The Machine and my bosses will be in a serious rage if the X Factor does not win."
RATM's Killing In The Name track has been chosen by internet campaigners because of its message of taking a stand against the establishment.
But both McElderry's song The Climb and RATM's Killing In The Name are ultimately released by the same record company, Sony BMG.
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