The first of a wave of strikes by London Underground workers in rows over pay and jobs will start today, threatening travel chaos for millions of passengers in the coming week.
Up to 200 Tube maintenance workers at depots on London Underground's Jubilee and Northern lines will go on strike for 24 hours from 7pm today in a row over pay and conditions.
The Alstom-Metro employees will also walk out for the same time on October 2, November 1 and November 27 after rejecting an "insulting" sub-inflation pay offer.
An indefinite overtime ban will also begin at a minute after midnight tonight.
Thousands of members of the Rail Maritime and Transport union and the Transport Salaried Staffs Association will strike for 24 hours from 5pm tomorrow in a major dispute over 800 job losses.
The walkout, to be followed by further stoppages in October and November, will badly disrupt Tube services as MPs return to Parliament after the recess and many people get back to work after the summer break.
Mayor Boris Johnson and Transport for London have announced contingency plans for dealing with the strike, with 100 extra buses being laid on, escorted bike rides, marshalled taxi ranks, and capacity for 10,000 more journeys on the River Thames.
Volunteers will be positioned at Tube, bus, and rail stations to help people with their journeys and provide maps and other information.
The move follows the breakdown of peace talks at the conciliation service Acas last week, with both sides blaming each other for the deadlock.
There was no sign of any last ditch talks over the weekend to try to avert the industrial action.
TfL warned that disruption is expected from late afternoon tomorrow and is set to last throughout Tuesday.
Mr Johnson said: "Londoners are a hardy bunch and I am sure a Tube strike will not deter us from getting around. I have asked TfL to pull out all the stops, but we must be clear that the RMT and TSSA plan to inconvenience Londoners for no good reason.
RMT general secretary Bob Crow said: "Instead of meaningless PR gimmicks from the mayor he should start telling his officials to take this dispute seriously and he should also start putting Tube safety before the dash to slash budgets.
"Boris Johnson was elected on a promise of protecting ticket offices and station staffing. Rather than throwing out red herrings like banning the right to strike he should get a grip on the lethal consequences that his officials' Tube cuts will have for both staff and the travelling public.
"The action is on and our members are finalising plans for picket lines across the network. RMT remains available for talks but we cannot and will not negotiate with a gun at our heads."
Gerry Doherty, general secretary of the TSSA, said the Mayor was behind the proposed job cuts, adding: "His plans to slash ticket office opening hours go considerably further than those he opposed in 2008 when trying to get elected as mayor and our members rightly see them as the forerunner for additional cuts in October when the Government delivers its dreaded spending review."
Meanwhile, TSSA members employed by Tube Lines will strike from 9am to 5pm on Tuesday in a separate row over pay.
Managers and clerical workers will also start an indefinite ban on overtime.
TUC General Secretary Brendan Barber said: "Tube staff are right to say there can be no compromise on safety and we fully support their action. The Mayor should honour his election promises and put a halt to these cuts."