Maintenance and upgrade workers employed by Tube Lines on the London Underground are to strike for 72 hours from 4pm on Tuesday of next week.
Some 81 percent voted for strikes in a recent ballot, with 91 percent backing for action short of a strike. The workers are members of the RMT union.
The dispute revolves around the refusal to grant Tube Lines employees the same pension rights and travel concessions as other London Underground workers.
The workers deal with maintenance and upgrades on the Jubilee, Northern and Piccadilly lines. A strike over three days in a row would cause severe disruption to the tube.
Tube Lines was formed as a public-private partnership in 2003, but the entire company was bought by Transport for London (TfL) in 2010 after a funding crisis.
RMT general secretary Bob Crow described the dispute as “a straightforward demand for parity with other tube staff”.
“Tube Lines is now a wholly owned subsidiary of TfL and there is simply no excuse for refusing to give equal pension and pass rights.”