Tube services could be thrown into turmoil next week after two unions encouraged its members not to work on trains that had “not been subject to safety checks”.
ASLEF and RMT unions have written to their members and told them not to bring trains into service if they do not believe they have been properly prepared.
The unions, along with TSSA and Unite, are already locked in discussions with London Underground over pay and shift arrangements for the new night Tube service.
Since the letters were issued, the ASLEF union claimed it was threatened with legal action by London Underground.
Finn Brennan, ASLEF's lead negotiator on the Tube, said: “Rather than sitting down with us to resolve this industrial dispute, London Underground are threatening to take legal action to stop our members doing their jobs safely by making sure their trains are fully safety checked before entering service.
“It is now clear that their agenda is not to resolve this dispute but to force through changes, no matter what the impact on staff and the safety of their passengers.”
Members of the RMT union have already banned working overtime and have now been instructed to take part in further action from 3.30am on July 28.
A letter asks members not to train or familiarise any underground employee or contactor in any working practice that is “not a normal, contractual and agreed job task work location of the trainee”.
In addition, train operators and instructor operators are urged to check whether their train has been “prepped within the previous 24 hours” before bringing it into service.
RMT members are then asked to not bring trains into service if they have “not been prepped” or have been “by unqualified personnel”.
Thousands of workers walked out earlier this month, with the underground network brought to a standstill and another 24 hour stoppage is planned from the evening of August 5.
Steve Griffiths, LU's chief operating officer, said: “We are working hard to resolve the current dispute, and are committed to continuing constructive discussions with all unions.
“We will never compromise on safety and are operating the underground safely for our customers and staff.
“Our measures to mitigate industrial action by union members include experienced managers undertaking some of their staff's duties.
“Any suggestion that we would use inexperienced staff is completely false.”
