Caledonian Sleeper staff have confirmed they will take industrial action after operators failed to deliver on “promises” to address “intolerable” stress caused by working conditions.
The RMT union claimed members have had their working lives “ruined” and that operators Serco did not address concerns which were raised.
Poor staffing levels and insufficient training have previously been blamed for the situation.
The union has now confirmed strike action and action short of a strike, after members previously voted in favour by more than 10 to one in a turnout of more than 80%.
Members have been instructed not to book on shift between 12pm on Sunday September 29 and 11.59pm on Tuesday October 1.
They have also been told to not to work any overtime or rest days, not to perform higher-grade duties and to work to their original job description from 12.01am on Wednesday October 2, until further notice.
RMT general secretary Mick Cash said: “The union is angry and frustrated that promises made to us to address the serious concerns of the Caledonian Sleeper staff at the end of July have not been honoured and that leaves us with no choice but to activate our industrial action mandate.
“RMT members have been put under intolerable personal stress as a result of the company’s mismanagement of the sleeper service.
“They know it, they have promised to do something about it but they have failed to deliver.
“The move to strike action is entirely Serco’s fault and the public will understand that.
“The union remains available for genuine and serious talks.”
Union representatives have had a number of meetings with the company through the joint working party.
They have reported “insufficient progress” has been made and that middle management has been “openly hostile” to finalising a settlement.
The operators admitted there have been problems while introducing the new Lowland Sleeper which were “challenging for everyone involved” and thanked staff for their efforts.
However, they called the action “completely unnecessary”.
Ryan Flaherty, Serco’s managing director of the Caledonian Sleeper, said: “We are deeply disappointed and frustrated at this industrial action by the RMT, but most of all we are bemused as they have been unable to explain what will bring this dispute to a resolution.
“We have met the RMT and company council on many occasions and the changes they have requested have either been completed or are under way, including the recruitment of more staff at Edinburgh, Glasgow and London for a six-month period whilst the new Mark 5 carriages settle in.
“This action is completely unnecessary and we urge the RMT to come back and tell us what they want. We are ready to go to mediation and hold further discussions.”