THE Choirboys, the trio dubbed the world's first choir boyband, are set to battle it out with Westlife for this year's Christmas Number One.

They are tipped to clinch the festive top spot with a cover of Eric Clapton's ballad Tears in Heaven.

But they will have to fight off stiff competition from boyband Westlife's duet with diva Diana Ross, When You Tell Me That You Love Me.

Last year, Band Aid 20 charity hit Do They Know It's Christmas? reached number one.

The Choirboys were discovered in their school choirs following a nationwide search across 50 cathedrals and churches in the UK.

Described as a mini version of the Three Tenors, they landed a £500,000 deal with music giant Universal Classics.

CJ Porter-Thaw, 11, and Patrick Aspbury and Ben Inman, both 12, are being guided by their co-manager - the Welsh former choirboy star Aled Jones.

Their debut album will feature choral music and interpretations of rock tunes, and their first single, tipped for Christmas success by music retailer HMV, is a rendition of Clapton's tribute to his lost son.

Diana Ross

Bookmakers William Hill are backing Westlife's rendition of the Diana Ross hit for Number One.

The boyband last enjoyed a Christmas Number One with I Have a Dream in 1999.

Other contenders this year include Tony Christie's big band cover of the Slade classic Merry Xmas Everybody.

G4 are also in with a chance, with a cover of the Johnny Mathis classic When a Child is Born.

Mariah Carey ballad Don't Forget About Us and Girls Aloud's See the Day are also favourites.

For the first time in a decade, the Christmas chart will be announced on Christmas Day, leaving the race for the Number One, which usually sells around 250,000 copies, more open this year.

Experts also say the rise in the download market means predicting the top-seller is more difficult this year.

Downloaders are less likely to react to the marketing surrounding a new release, meaning tracks released in the last week before Christmas are not the sure-fire bets they once were.

HMV singles buyer Stewart Allan said: "The charts can be fairly predictable these days but the one time you just don't know what's going to happen is at Christmas.

"Often there's a novelty hit that comes out of the blue or a big charity release, and sometimes there's a really hot new boy band or girl group that's pretty unstoppable.

Surprise

"I'm sure this Christmas will be no different and it wouldn't surprise me if a song emerges that we don't even know about yet."

William Hill's spokesman Rupert Adams said: "Over the years, Christmas Number One betting has become a national institution and we could not have hoped for a more competitive and open field.

"At present, Westlife and Diana Ross are the 9/4 favourites, but there are so many contenders that I am sure we will see a number of different favourites over the course of the next two months."

HMV anticipated Christmas Number One contenders and William Hill odds:

:: The Choirboys, Tears in Heaven (12/1)

:: Tony Christie, Merry Xmas Everybody (8-1)

:: Westlife with Diana Ross, When You Tell Me That You Love Me (9/4)

:: G4 featuring Robin Gibb, When a Child is Born (5-1)

:: Girls Aloud, See the Day (10/1)

:: Mariah Carey, Don't Forget About Us (40/1)

:: Robbie Williams, Advertising Space (12/1)

:: Crazy Frog - title tbc (7/2)

:: Coldplay, Talk (33/1)

:: James Blunt, Goodbye My Lover (8/1).