London jammed with vast crowd of mourners

The vast police operation to oversee today's funeral started last night as hundreds of thousands of mourners converged on London. Four thousand Scotland Yard officers went on duty at 4am in the capital and hundreds more started preparing to police the cortege route up the M1.

With up to six million people expected to line the three-and-a-half-mile route from Kensington Palace to Westminster Abbey and hundreds of thousands of other mourners waiting along the motorway, the day is a logistical nightmare for the police.

However, the Metropolitan Police, which has extensive experience in dealing with mass gatherings believes it has prepared for every eventuality. The main dangers for possible injury and unrest are if people become crushed behind the barriers as they attempt to see the coffin pass by.

People will be allowed on to the motorway bridges above the south- bound carriageway. "We don't want anyone throwing themselves or objects, even flowers, on to the motorway," said a spokeswoman from Bedfordshire Police.