The Met police will launch a major new crackdown on crime, disorder and anti-social behaviour in the West End later today.
The campaign, called Operation Trafalgar, includes an area with a bed in it to help worse-for-wear revellers sober up.
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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.