Mariah Carey is the Christmas Queen

Mariah Carey is preparing to pull on her Santa suit a month early - she is set to switch on London's glittering Christmas lights.

The singer will flick the switch at the U.K. capital's Westfield Shopping Centre later this month - and is looking at videos from her festive hits All I Want For Christmas and Santa Baby to stage a dramatic entrance.

A source tells Britain's News Of The World newspaper, "It's going to be Christmas themed. She's been looking back at her Santa Baby video for inspiration. She wants to make it a big deal."