Hundreds of thousands of people took to the streets last time London was visited by the Formula One travelling circus back in July 2004.
During the event former F1 World Champion Nigel Mansell threw his support behind the idea of a London race, saying that if it were to become a reality "it would be one of the best street circuit races in the world":
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Paramedics were on standby outside the police cordon as armed officers stood by the property.
A team of researchers has taken samples from the ten busiest London Underground lines to work out which are the dirtiest.
The action comes on top of an emergency timetable which has seen hundreds of trains a day being axed.