London's mayor raised concerns Tuesday about the lack of urgency given to policing the 2012 Olympics. Boris Johnson, who has presided over the capital since May, said senior advisers have warned him that "we are getting behind" in security with about four years left until the games. "I think it is vital that we establish very soon what the security architecture is going to be for the games," Johnson told a parliamentary committee. "That is to say, we need to know: are we going to have police milling around? Are we going to have lots of security arches? Are we going to rely on intelligence? "What is our approach to policing the games going to be? I'm afraid that not enough work has been done on this so far."