A number of Tube drivers in London are at the beginning of a 24-hour walkout in anger at the lack of “respect and dignity” the union says its drivers are afforded.
Two Tube lines - the Central and Waterloo & City - is used by nearly a million passengers a day and their closure will cause “severe disruption” for commuters and visitors, London Underground has said.
There is currently no service on the Waterloo & City at all and on most of the Central, however there is a limited service between White City and Ealing Broadway, and Leytonstone and Epping.
Travellers have been urged to check their route before leaving.
Tickets are valid on local buses, with extra buses commissioned for key routes, Transport for London said.
Nigel Holness, London Underground’s Operations Director, said: “We will have staff and volunteers across the network to help customers with their journeys, but I advise people to plan ahead and check before they travel.”
Finn Brennan of train driver union Aslef said: “This dispute has been brought about by management intransigence on a range of issues, but at its heart is management's refusal to treat drivers with the respect and dignity they deserve at work.
Video: London Underground apologises for strikes
“Our members will not tolerate a situation where vulnerable people leave sickness review meetings in tears and drivers with years of good and long service are threatened with disciplinary action for a delay of 33 seconds in leaving a terminus.”
Meanwhile, leaders of the Fire Brigades Union (FBU) in England and Wales will be meeting with a government minister today to discuss pension disputes.
General Secretary Matt Wrack and Fire Minister Penny Morduant will try to “find a fair resolution” on an issue that has resulted in 40 walk-outs since it began over a year ago.
In an open letter to Ms Morduant, Matt Wrack writes: “As we have set out consistently, the FBU is always willing to meet to discuss a way forward.
“We have never walked away from talks or refused to meet.
“Nevertheless, talks must be conducted with a view to resolving the matters between us.”
Additional reporting by PA