Up to 40 stations that do not interchange with other lines have been shut down for the foreseeable future, while the Waterloo and City line and night Tube services will not run from Friday.

Buses in the capital will be reduced and people are being urged "not to use public transport for anything other than essential journeys".

Asked at the daily press conference on Wednesday whether London faced a possible shutdown like other European cities, the Prime Minister said: "We live in a land of liberty, as you know, and it's one of the great features of our lives that we don't tend to impose those sorts of restrictions on people in this country.

"But I have to tell you we will rule nothing out and we will certainly wish to consider bringing forward further and faster measures where that is necessary to suppress the peak of the epidemic, to protect our NHS, to minimise casualties and to minimise suffering.

"Absolutely we do not rule it out, because it would be quite wrong to do so. We do not rule out taking further and faster measures in due course."

The Telegraph understands that London is likely to go into a lockdown as early as the weekend under the most dramatic measures yet to curb the spread of coronavirus. London has more cases than anywhere else in the country (see map below).