Simon Cowell has tightened his stranglehold on the British music industry by securing a third successive Christmas number one for the winner of X Factor, his ITV karaoke contest.

Leon Jackson, an 18-year-old shop assistant from West Lothian, was this series’ winner. His debut single When You Believe becomes the fastest selling single of the year with 275,000 sales - more than the rest of the top ten combined.

“I’m absolutely over the moon. It’s the best Christmas and birthday present ever,” he said. “Having the Christmas number one is an amazing ending to an amazing year and I’m overwhelmed and thrilled.”

Dannii Minogue, the teenager’s mentor on the television programme, added: “It’s amazing.”

Cowell, a millionaire pop music producer, gives a record deal to the winner of each series of X Factor. That accolade appears to ensure that their first single goes straight into the charts at number one, but Jackson has sold far fewer copies than his predecessors.

Shayne Ward sold 742,000 copies of his debut to earn the festive top spot two years ago, Leona Lewis, the 2006 X Factor winner, managed 571,000.

Alan Jones, a chart consultant with the industry magazine Music Week, said: “The charts do tend to be cyclical and you get runs of things. Every Christmas number one of the 21st century has been either a novelty, reality or charity single.

“Even though it’s the third Christmas in a row we’ve had an X Factor winner at number one, the last two singles have done rather less well than Shayne Ward.”

Jackson was a surprise winner with Rhydian Roberts, a Welsh operatic singer, the favourite to win the public vote.

Previous X Factor winner Lewis is placed third in the Christmas chart with Bleeding Love, one position below a 'duet' between Katie Melua and the late Eva Cassidy.

The old Pogues and Kirsty MacColl hit, Fairytale Of New York, completed the top four after BBC Radio One offered the single a publicity boost. The station decided to remove the word “faggot” from the well-known chorus because it was felt it might cause offence to some, before admitting they had made a mistake and reinstating it.

Explore Music

• CD Reviews

• Live Reviews

• Classical

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010