London Underground workers are to take six days of strike action in an escalating row over the sacking of two Tube drivers, threatening travel chaos for millions of passengers.
The Rail, Maritime and Transport union said its driver members on the Tube will walk out for between nine and 24 hours from Monday May 16 to Friday May 20 and again from Monday June 13 to Friday June 17.
The strikes will effectively disrupt the Tube over a period of two weeks, with the union saying the action will have a "major impact" on services.
The move follows a 2-1 vote in favour of industrial action by RMT members in protest at the dismissal of Northern Line driver Eamon Lynch and Arwyn Thomas, a Bakerloo Line driver. Both men have taken a case of unfair dismissal to an employment tribunal.
The union said 1,500 drivers - around half the total - will take strike action, threatening the worst disruption on the Tube since a series of strikes last autumn in a separate row over jobs.
Both men were given an "interim relief" by an employment tribunal, although their full cases have yet to be heard. The RMT said interim relief was only granted by a tribunal where there was the clearest possible evidence that an employee had been dismissed on the grounds of their trade union activities.
Mr Lynch is the RMT's Bakerloo Line drivers' health and safety representative.
The union claimed that Mr Thomas, a long-standing RMT activist, was sacked on "trumped-up" disciplinary charges following allegations made against him after an incident during last year's strike. LU strenuously denies the union's claims.
RMT general secretary Bob Crow said: "The solution is simple - LU should accept that they have been found out, get these drivers back to work doing the job that they are being paid to do and bring an end to the constant harassment of union activists whose only crime is fighting cuts to jobs and safety."
LU managing director Mike Brown said: "Just 29% of the 1,300 drivers balloted voted for this strike. The cases concerned are still going through the employment tribunal process and Transport for London will of course respond to whatever conclusions are reached in this process."