Video: X Factor stars sing at Downing St
X Factor stars sang for the Prime Minister at the Christmas light switch on in Downing Street.
James, Jahmene and Christopher were joined by judge Nicole Sherzinger - and loads of kids - as they sang outside the famous door to Number 10.
David Cameron was there to see the festive mini concert on his front doorstep.
The X Factor final takes place on 8 December in Manchester.