The amateur footage below shows the Tate Modern gallery and Trafalgar Square flooded by revellers dressed in their red and white fancy dress for SantaCon 2012.
This year's SantaCon saw revellers dressed in full Father Christmas gear in a part pub crawl, part flash-mob.
In the video, a section of Santas chant: "What do we want?", with a chorus of shouts responding "Christmas!"
The other Father Christmases question: "When do we want it?", with the others replying: "Now!"
SantaCon has taken place in 27 countries and 275 towns and cities across the world.