London Underground maintenance workers are set to take indefinite industrial action from next week.

The RMT Union have confirmed that fleet members will be ‘working to rule’ from Tuesday, March 7 until further notice.

This will include not working any overtime or attending training courses outside of normal working hours, not carrying out any work of a higher grade than they are employed for, not changing any shifts or locations to help with maintenance and refusal to work without a first aider on site.

In a recent ballot, 67 per cent of fleet members voted for strike action and 88 per cent voted in favour for action short of a strike.

RMT general secretary, Mick Cash, said: “The current level of flagrant abuse and ignorance of long-standing policies and procedures by London Underground is appalling and the anger among RMT Fleet grades members was clearly demonstrated in the ballot results.

“The continued failures by the management side have left us with no option but to begin a campaign of industrial action.

“RMT’s position could not be clearer and it is down to London Underground to start taking this list of grievances seriously, to stop trying to impose fundamental changes to agreed policies and working conditions and to halt the bullying and harassment of our reps.

“RMT remains available for serious talks.”

The RMT’s list of grievances includes reduced staffing levels without consultation, failing to hire enough additional staff to cover the Night Tube and ‘actively attacking’ union representatives.

A spokesman for Transport for London said: “We urge the RMT leadership to work with us constructively on the issues it has raised, rather than threaten unnecessary industrial action.”