Hundreds of London Underground workers are to be balloted for strikes in a series of rows over new rosters, agreements and the use of outside contractors, it was announced today.
The Rail Maritime and Transport union said 750 staff will vote over the next few days, with the result due next week.
The union accused LU of ripping up agreements, "bulldozing through" shift patterns and of threatening job security through increased use of outside contractors, affecting staff such as maintenance workers.
General secretary Bob Crow said: "LU seem to be hell-bent on confrontation by tearing up the signals framework agreement and by unilaterally introducing new working practices which mean they can make people work what hours they like, when they like.
"On top of that, our members' job security is being undermined by the handing over of work to external private contractors which could be done internally."
A Transport for London spokesman said: "London Underground is planning to introduce a roster covering 24 hours a day, seven days a week to ensure planned engineering staff are always available.
"Whilst this agreement already exists, it is in fact the RMT that is seeking to break our agreements.
"We have consulted fully with staff and unions on the proposed changes to rosters, and we continue to discuss this at a local level.
"The RMT leadership should stop threatening industrial action again and resume meaningful talks on this issue. Any action will do nothing except lose RMT members pa