A 48-hour London Underground strike is under way after a High Court battle yesterday failed to secure an injunction stopping the walkout.
Maintenance staff working for Tube Lines have gone on strike on the Piccadilly, Northern and Jubilee lines in a row over jobs, pay and working conditions.
Tube Lines went to the High Court to question the legality of the strike ballot, but the judge threw out its claim for an injunction.
The train maintenance firm claimed the RMT had given information that 47 advanced train maintenance staff had voted in the strike ballot, when only 30 were employed, the Guardian has reported.
At a court hearing in London, Justice Tugendhat said he had reached a "clear view" that he should not grant an injunction. Tube Lines said in a statement the court had asked for more information and there would be a further hearing on 9 July.
Bob Crow, general secretary of the RMT, said: "This is a massive victory, not only for the RMT and our members, but for every group of workers who stand and fight against job cuts and attacks on working conditions. The strike goes ahead and will be solidly supported. We expect major disruption across the network."
Andrew Cleaves, Tube Lines' acting chief executive, said: "We urge the RMT to pull back from taking this needless action that would unnecessarily inconvenience the travelling public. We ask the RMT to return to the negotiating table and reconsider the pay offer we have made to its members.
"Only on Tuesday, the government announced a two-year pay freeze for public sector workers, which the RMT publicly criticised. We are surprised they have then rejected a good pay deal for their own members.
"A pay increase of 3.7% this year with the possibility of an extra 0.5% subject to productivity changes and then RPI, plus a guaranteed 0.5% for the two years that follow, is a very good offer, especially in light of today's financial climate."