A 24-hour strike by hundreds of London Underground maintenance workers was said to be "solidly supported" today, with warnings of disruption to services.
Members of the Rail, Maritime and Transport union walked out at 6.45am, and plan further stoppages from the same time every Sunday from February 14 until the dispute is resolved.
The action involves workers on lines which used to be maintained by Metronet, including the Victoria, Bakerloo and Central routes.
London Underground (LU) said it was intending to operate a good service during the industrial action.
But the union warned of disruption. RMT leader Bob Crow said: "Our members are rock solid in their support for this strike and in their determination to defend their jobs and working conditions.
"LU have been hell-bent on confrontation through their tearing up of the signals framework agreement and through the unilateral introduction of new working practices which mean they can make people work what hours they like, when they like."
Phil Hufton, LU's chief maintenance officer, said: "Londoners will share our dismay at the RMT's leadership's attempts to jeopardise the Tube's operation over this issue.
"We are planning to introduce a roster covering 24 hours a day, seven days a week, to ensure planned engineering staff are always available. That agreement already exists, but the RMT is trying to tear it up.
"We have consulted fully with staff and unions on the proposed changes and we are prepared to continue discussions with the RMT. They should stop threatening industrial action at every opportunity, when all that will do is lose their members more pay.
"Despite this unjustified threat, it is our intention to operate a good service across the network during industrial action."Reuse content