Almost the entirety of central London has been brought to a standstill as strike action on the tube continues.
Millions of commuters face travel misery and difficulty as the Rail, Maritime and Transport union (RMT) and the Transport Salaried Staffs Association (TSSA) continue their 24-hour walkout in a dispute over jobs and ticket office closures.
A number of Tube stations across zone 1 have been closed by the strike, which is creating disruption across the city.
Transport for London (TfL) has advised passengers on their options and warned there will be a severely reduced service across the Tube network all day.
National Rail services have not been affected by the strike, but key interchange stations like Victoria and Waterloo are closed. Piccadilly line services will run between Hammersmith and Heathrow Terminals 1, 2 and 3, but there will be no service to Terminals 4 or 5.
Meanwhile, the Victoria and Waterloo & City lines have no operating services at all, with outer London services on other tube lines severly affected.
RMT general secretary Mick Cash said: "Our members are out in force across London this morning in the fight for jobs and safety.
"This action has been forced on us by savage job cuts which have reduced London Underground to an under-staffed death trap at a time of heightened security.
"Even senior Tube bosses have admitted we are correct in our risk assessment of the the impact of the 900 station job cuts.
"The solution is in the hands of the Mayor and his officials. They need to come up with serious and urgent plans designed to address the core issues at the heart of this dispute and a schedule for staffing back up on the stations to a level our reps believe is safe and sustainable.
"RMT remains available for further talks around that programme of action."