A strike by London Underground workers will hit services for the rest of the week and into the Friday rush-hour, union leaders have claimed.
Members of the Rail, Maritime and Transport union (RMT), who maintain and upgrade the Jubilee, Northern and Piccadilly lines and deal with emergencies across the network, will walk out at 4pm today until the same time on Friday in a row over pensions.
The union said the action, which also involves staff who respond to emergencies across the Tube system, will have a big impact on services, although London Underground (LU) denied this, maintaining there would not be any significant affect.
The union will mount a picket line later today at the London headquarters of Tube Lines
RMT general secretary Bob Crow said: "The inexplicable refusal of London Underground to agree to equalise pensions and benefits rights for our maintenance members is deeply suspect and points clearly to a secret plan to re-privatise this work in an action replay of the PPP (public private partnership) disaster.
"We understand there are already vulture companies hovering in the wings for another shot at robbing London blind through PPP2 and reducing the network to chaos."
LU managing director Mike Brown said: "There are no plans to repeat the PPP structures of the past. LU has recently taken the maintenance of the Jubilee fleet of trains back under our direct control. Our actions speak for themselves.
"We are committed to proper discussions on the future of Tube Lines and that includes all our staff.
"Since Tube Lines transferred to TfL in June 2010 we have been fully focused on the upgrade of the Jubilee line which the PPP totally failed to deliver. It has now been delivered with faster, more frequent services for Tube customers."
Jon Lamonte, Tube Lines' chief executive, said the strike will have no significant effect on Tube services, adding: "We have well-practised contingency plans in place to ensure that the essential maintenance required on the railway can either go ahead as planned or can be rearranged. We do not and will not put passenger or staff safety at risk."
Firms should use the strike to test any flexible working plans they have for the Olympic Games, a specialist has suggested.
Michael Stephens, of video conferencing firm LifeSize, said: "If the strikes go ahead they will undoubtedly lead to severe delays which could cost businesses millions. When that cost is combined with a disgruntled workforce, businesses could be faced with a serious problem."