The "X Factor" notched up a Christmas pop chart double on Sunday, with this year's winner of the TV talent show taking the coveted number one single spot and last year's victor notching up the best-selling album.

As expected, Scottish singer Leon Jackson, 18, who won the fourth series of the show last week, went straight to the top of the singles chart with his debut release "When You Believe", a cover of the Mariah Carey and Whitney Houston hit.

Bookmakers were so certain that Jackson, who was given a million pounds recording contract after beating Welsh singer Rhydian Roberts in the "X Factor" final, would be the Christmas number one that they had started paying out three days ago.

"Christmas number one was one of the great Christmas traditions with thousands of small wagers placed each year as the big boys battled it out for the top spot but the X Factor has killed off the fun as no one dare go up against it," said Rupert Adams, spokesman for bookmaker William Hill.

"It has now got to the stage where we are already odds on that the X Factor winner will have the Xmas 1 in 2008."

Elsewhere there was little change in the top 10, according to the official UK Charts Company.

In second place was last week's chart topper, "What A Wonderful World", Katie Melua and the late Eva Cassidy's version of the classic Louis Armstrong song.

Last year's "X Factor" winner Leona Lewis was in third place with "Bleeding Love", while "Fairytale Of New York" by the Pogues and Kirsty MacColl climbed to fourth, boosted by BBC radio's aborted attempt to censor its lyrics.

American rapper Soulja Boy Tellem dropped to fifth with "Crank That (Soulja Boy)", ahead of Mariah Carey's "All I Want For Christmas Is You".

Leona Lewis, who won the Christmas number one single title last year, added the album crown to her list of accomplishments this time round.

Her album "Spirit" held off "Back Home" by reformed boy band Westlife for the top spot, with "Call Me Irresponsible" by crooner Michael Buble in third.

"Vivere", the best of Andrea Bocelli, climbed two places to fourth with Californian rockers the Eagles staying fifth with "Long Road Out Of Eden".