operation is underway on the streets of london. the it is ji preparing to say a final formal farewell to former british prime minister margaret thatcher. anna bell roberts has the details from london this morning. annabell, good morning. >> reporter: good morning. well, margaret thatcher's coffin has just been moved from a chapel at the palace of westminster behind me where it was overnight and is in the process of being transferred on to the back of a horse drawn first world war gun carriage. it will then be driven the short distance through the streets of london to st. paul's cathedral for the funeral which is due to start in 40 minutes. that is being attended by the queen. as you can see, there are soldiers there for this funeral. now there are 4,000 or so policemen on the streets of london to ensure this event passes off peacefully. there have been sniffer dogs checking the route. there are spotters on the roofs. but above all, they're there to ensure that any protest does not