Sam Bailey has become the odds-on favourite to score the 2013 Christmas number one following her X Factor victory on Sunday night.

The 36-year-old – who triumphed over teenage singer Nicholas McDonald in the weekend-long show – has her debut single, a cover of Demi Lovato’s Skyscraper, released on Monday.

And bookies – who paid out to the tune of £250,000 following her win – have now offered odds of 2-5 on her being number one when the Christmas chart is unveiled on December 22.

“Bailey now looks a cert for this year’s Christmas number one,” said Ladbrokes spokesman Alex Donohue.

“We fully expect her fans to rush to the shops to spend their winnings on a copy.

Sam will face stiff competition for the top spot from Australian rockers AC/DC, after a Facebook campaign was launched to get their 1979 track Highway To Hell to number one for Christmas instead of the X Factor winner.

Susan Boyle’s O Come All Ye Faithful – which sees her duetting with Elvis – and the Big Reunion Christmas single I Wish It Could Be Christmas Everyday are also among contenders to top the charts.