Commuters travelling in London today are facing “severe disruptions” as the 48-hour Tube workers strike gets underway.
Members of the Rail, Marine and Transport Union (RMT) have mounted picket lines outside of stations after walking out for 48 hours at 9pm last night in protest at plans to close Tube ticket offices.
There were almost 8,000 buses on the roads - the most ever operated in London - after an extra 266 were put into service.
The union said the closure of ticket offices will cost hundreds of job losses and threaten safety.
But London Underground (LU) maintains that staff would be better employed on station concourses.
Large queues built up as early rush-hour passengers waited until 7am for the first Tube trains to run. At Euston station in north London, customers crowded around the entrance to the Underground, while at London's Victoria station, passengers pouring off mainline trains were confronted with a wall of people waiting for Tube services.
In pictures: Tube strike April 2014
In pictures: Tube strike April 2014
1/4 Tube Strike
Commuters travel on the Northern Line of the London Underground which is running a limited service due to industrial action on April 29, 2014 in London, England.
2/4 Tube Strike
Commuters at Stratford Underground, Overground and DLR Station in east London, on the first day of a 48 hour strike by tube workers on the London Underground over ticket office closures.
3/4 Tube Strike
Commuters prepare to travel on the District Line of the London Underground during strike action on 30 April, 2014
4/4 Tube Strike
Commuters wait at Victoria tube station for limited service trains in London, Britain, 29 April 2014.
The decision to strike has been heavily criticised by LU and the London Mayor Boris Johnson, who accused the RMT leadership of being “set against modernisation” and of lacking “fresh ideas of its own”.
If the dispute is not resolved, RMT members say they will stage another walkout - this time for 72 hours - from 9pm on Monday 5 May.
The RMT said its members were solidly supporting the industrial action, as the union again attacked Mr Johnson over the future of ticket offices.
TFL has produced a document of travel advice to customers and said it plans to run for extra bus and river services. But those services are expected to be very busy, and TFL is advising commuters to leave plenty of extra time to finish their journeys.
The RMT also launched a 48 hour strike from 3am today on the Heathrow Express in a separate row over jobs, pay and cuts.
Leaders of the RMT held a last ditch meeting with LU at the offices of the conciliation service Acas yesterday in a bid to resolve the row over Tube ticket offices, but the talks only lasted a couple of hours and broke up with no sign of a breakthrough.
The union said it had put forward proposals which it believed could have led to the industrial action being suspended.
RMT acting general secretary Mick Cash said: "London Underground have dug themselves into an entrenched position and have refused to move one inch from their stance of closing every ticket office, in breach of the agreement reached previously through Acas which enabled us to suspend the previous round of action.
Mr Johnson said: "I urge the RMT to call off this pointless strike and get back round the table with London Underground and the three other unions who've chosen not to strike.
"More than 600 people have asked for voluntary redundancy and yet, without consulting any of their own members the RMT is suddenly insisting that London Underground halt this process.
"Commuters and businesses will suffer because a few narrow minded union barons are currently flexing their muscles in a fight for the leadership of a union where just 30 per cent of members support a strike."
These are the services that are expected to run today:
Bakerloo line: No service due to strike action. TFL hopes to restore a service between Queens Park and Elephant & Castle, with some stations closed, as soon as possible.
Central line: Service operating between White City and Ealing Broadway, between West Ruislip and North Acton, between Epping and Leytonstone and between Hainault and Leytonstone only. No service on the rest of the line.
Circle line and Waterloo and City Line: No service on either, but some stations will be served where other lines share the track.
District line: Train service operating between Ealing Broadway and High Street Kensington and between Wimbledon and Upminster.
Hammersmith and City line: Service operating between Hammersmith and Moorgate only. No service on the rest of the line
Jubilee line: Service operating between Stanmore and Finchley Road only, approximately every 10 minutes.
Metropolitan line: Service operating between Harrow-on-the-Hill and Aldgate only
Northern line: Service operating between Edgware and Golders Green and between High Barnet and East Finchley/Mill Hill East
Piccadilly line: Service operating between Acton Town and Heathrow Airport, approximately every 10 minutes.
Victoria line: Service operating between Seven Sisters and Brixton, approximately every 8 minutes with some stations closed.
DLR, London Overground, trams and other rail services, buses and river buses: Normal service.