London 2012 Organising Committee chairman Sebastian Coe (L) moves to stop a volunteer heckling Britain's Prime Minister David Cameron during a meeting with London 2012 Olympic and Paralympic Games volunteers, as they prepare for the start of the games in a month's time at the Uniform Distribution and Accreditation Centre, (UDAC) in east London June 26, 2012. The volunteer, who yelled, "Shame on you, Mr. Cameron" was escorted out. [Photo/Agencies]

Britain's Prime Minister David Cameron talks to London 2012 Olympic and Paralympic Games volunteers, as they prepare for the start of the games in a month's time at the Uniform Distribution and Accreditation Centre, (UDAC) in east London June 26, 2012. The London 2012 Olympic games run from July 27 to August August 12. [Photo/Agencies]