Earlier this afternoon, Boris Johnson visited Clapham Junction, an area which saw sustained rioting and looting last night. He was heckled by angry residents who demanded an explanation for the lack of police presence. "What about Mark Duggan"? shouts one.
Visibly flustered, Johnson struggles to respond. Reportedly, Nick Clegg received similar treatment on a trip to Birmingham. No-one should underestimate the political difficulty that these riots will represent for the coalition's top command.