Katherine Jenkins to star in Doctor Who Xmas special

Katherine Jenkins, the Welsh mezzo-soprano and occasional TV presenter, is to make her acting debut on this year's Doctor Who Christmas special. Veteran actor Michael Gambon will also star in the 60-minute seasonal episode which has been described by the show's lead writer Steven Moffat as "the most Christmassy Christmas special" seen since the sci-fi drama returned in 2005.

Jenkins and Gambon will appear on the show as the Doctor's assistant Amy Pond - played by Karen Gillan - heads off on honeymoon. The guest stars' roles are yet to be revealed although Moffat promises a showstopper to rival last year's two-part Christmas special which saw David Tennant bow out after four years as the Doctor.

"We're going for broke with this one," Moffat said of the first Christmas special to star Matt Smith as the eleventh Doctor. "It's all your favourite Christmas movies at once, in an hour, with monsters. And the Doctor. And a honeymoon."

Moffat told the Guardian that he had not realised that it was Jenkins's first major acting job. Previously her acting CV was limited to a cameo in the ITV soap opera Emmerdale in 2007, in which she played herself opening a village fete. "She is brilliant – she is a great singer and a great performer," he said.

Jenkins follows in the footsteps of fellow singer Kylie Minogue, who starred as a waitress on the Titanic in 2007's Christmas special 'Voyage of the Damned'. That episode garnered Doctor Who's highest audience figures since 1979, with 12.2 million tuning in.

Meanwhile signing up Gambon - the star of Dennis Potter's acclaimed 1980s TV series The Singing Detective and more recently known as headmaster Albus Dumbledore in the Harry Potter films - had been a coup for Doctor Who, Moffat added.

"Michael Gambon is as distinguished an actor as I can imagine and the fact that he was Dumbledore means that he is already known to millions of children." ·