© Licensed to London News Pictures. LONDON, UK  05/07/11. Alastair Campbell, Chairman of Fundraising at Leukaemia and Lymphoma Research, and the Mayor of London, Boris Johnson, ride in Trafalgar Square alongside four school boys who are set to cycle from London to Lisbon in aid of the blood cancer charity. Alastair Campbell, L-R Harry Pearson-Gregory (16), Louise Metcalfe (17), Alastair Campbell, Boris Johnson and Archie Gilmour (17, Boris Johnson's godson), for more information see www.beatbloodcancers.org. Please see special instructions for usage rates. Photo credit should read Matt Cetti-Roberts/LNP