(Yahoo News) - London Underground passengers are being warned of a "severely reduced" service after Tube staff began a 24-hour strike at 6pm on Sunday
Transport for London said it was likely that most stations in Zone 1 would be closed for the entire period.
Key stations including Victoria, King's Cross, Waterloo, Paddington, Euston, Bank and London Bridge will have no Underground service.
Trains will run on the Piccadilly line between Hammersmith and Heathrow Terminals 1, 2 and 3 - but not Terminals 4 and 5.
The Victoria and Waterloo & City lines will have no service, while every line is expected to be severely affected.
The action, by members of the RMT and TSSA unions, is part of a long-running dispute over ticket office closures.
According to the unions, more than 800 jobs have been lost, while staff are allegedly being abused by passengers queuing at ticket machines.
TSSA representatives turned down the latest offer, echoing an earlier decision from the RMT.
The TSSA's general secretary, Manuel Cortes, said: "Whilst they accept the offer of more staff is a step in the right direction to restoring Tube safety standards, they do not believe the offer will return those standards with the urgency that is now needed.
"We remain committed to taking part in further talks to seek a resolution to this dispute."
In a message to union members, RMT general secretary Mick Cash said: "Despite the best efforts of your negotiators over many days, London Underground has not put forward (an) acceptable proposal to address the staffing and safety issues."
Earlier, London Mayor Sadiq Khan described the strike as "pointless".
He said: "This strike is going to be a huge inconvenience to commuters, tourists and TfL staff.
"And it is pointless. There is a good deal sitting on the table that will ensure station safety and staffing levels across the Tube network."
Mr Khan added: "I am willing to carry on negotiations.
"This historic dispute has nothing to do with the millions of Londoners this strike is punishing."
London Underground's chief operating officer, Steve Griffiths, said: "There is no need to strike.
"We agree that we need more staff in our stations and have already started to recruit 200 extra staff.
"Taking into account existing vacancies and natural turnover, this means that over 600 staff will be recruited for stations this year."