The Darkness have been a sensation in 2003

The Darkness song Christmas Time (Don't Let the Bells End) is now 8-13 with William Hill and 1-3 with Ladbrokes.

Gary Jules' Mad World, featured in the film Donnie Darko is at 6-5 on William Hill and at 13-8 on Ladbrokes.

"We have seen a considerable amount of money for Gary Jules," said a William Hill spokesman.

The Christmas chart will be unveiled on Sunday.

The Pop Idol 12 single, which had been an early favourite, was fading in the charts race, with odds of 9-1 on William Hill and 10-1 on Ladbrokes.

LADBROKES ODDS 1-3 - The Darkness, Christmas Time (Don't Let the Bells End) 13-8 - Michael Andrews feat Gary Jules, Mad World 10-1 - Pop Idol 12, Happy Xmas (War is Over) 50-1 - Ozzy and Kelly Osbourne, Changes 50-1 - Avid Merrion, Proper Crimbo

Ozzy and Kelly Osbourne's Changes currently has odds of 33-1 with William Hill and 50-1Ladbrokes, despite topping the charts on Sunday.

The Darkness have released their single on three different CD formats in the race, one of which costs just �1.99, which is thought to be helping their chart chances.

The Idols' song was recorded by all 12 of the TV talent show's finalists before they began to get voted out of the contest.

WILLIAM HILL ODDS 8-13 - The Darkness, Christmas Time (Don't Let the Bells End) 6-5 - Michael Andrews feat Gary Jules, Mad World 9-1 - Pop Idol 12, Happy Xmas (War is Over) 33-1 - Ozzy and Kelly Osbourne, Changes 50-1 - Avid Merrion, Proper Crimbo

But, as a song about war ending, it has been criticised by some as a poor choice given the current situation in Iraq.

CND have called for profits to go to humanitarian organisations and called the release "insensitive and offensive".

The Christmas number one will be announced one day after this year's Pop Idol winner is chosen by viewers.

The battle is down to the final two - Mark Rhodes and Michelle McManus - who will spend the week touring the country on their own battle buses.