Photostream : Christmas at Number 10

Christmas at Number 10 : Reindeer out side Number 10 where they were part of a Christmas party to entertain families of British servicemen and women. December 20, 2010 (Photo : Number 10.Gov.UK)

Christmas at Number 10 : Reindeer out side Number 10 where they were part of a Christmas party to entertain families of British servicemen and women. December 20, 2010

Christmas at Number 10 : Snow at the entrance to Number 10

FILE : Britain's Prime Minister David Cameron, second right, with his wife Samantha, in white coat, and children who have won competitions on childrens TV pose for the cameras as the Downing Street Christmas lights are turned on outside No 10 Downing street, in London, Wednesday, Dec., 8, 2010. (AP Photo / Alastair Grant)

FILE : Britain's Prime Minister David Cameron (C) and his wife Samantha join children's television programme 'Blue Peter' competition winners to switch on the Christmas Tree lights in Downing Street in London December 8, 2010. REUTERS/Luke MacGregor

FILE : Samantha Cameron, the wife of Britain's Prime Minister David Cameron, helps to wrap one of 150,000 Christmas presents at the Salvation Army headquarters in Southwark, London December 6, 2010. The presents will be given to to underprivileged familes in Britain at Christmas. REUTERS/David Parker/Pool