Britons David Millar and Bradley Wiggins will be the riders to watch when the Tour de France starts with a 7.9-km prologue in London on Saturday.
London-born Cofidis rider Wiggins won the prestigious Dauphine Libere opening time trial last month while Millar, a winner of the Tour prologue in 2000, will bank on experience in his bid to grab the yellow jersey.
Both must hold off challenges from time trial world champion Fabian Cancellara of Switzerland and American David Zabriskie.
The prologue starts at Trafalgar Square and passes Buckingham Palace, Westminster and Hyde Park before finishing in The Mall.
Two years to the day after 52 London commuters were killed in attacks on three underground trains and a bus, 5,000 police officers will be deployed along the course.