Caledonian Sleeper services will be cancelled for two days as staff strike over what unions described as “intolerable pressure”.
Negotiations have broken down between the RMT and Serco, which runs Sleeper services, with the operator accused of “slamming the door on any settlement”.
Workers will now take industrial action, joining picket lines in London and Scottish stations, forcing the train operator to cancel all services on Sunday and Monday.
Serco said it is attempting to make arrangements with other train companies to help stranded passengers travel, as well as refunding fares.
The strike action follows failed negotiations between the two sides, with the RMT alleging Serco has not addressed “a raft of serious concerns raised by staff that have ruined working lives and placed the workforce under intolerable pressure”.
RMT general secretary Mick Cash said: “Every effort RMT has made to settle this dispute with Serco has been kicked back in our faces.
“There was an opportunity to reach an agreement that would address the matters at the heart of the dispute this week but once again Serco squandered the opportunity and chose instead to string us along. That is no way to run a railway.
“The union is angry and frustrated that promises made to us to deal with the serious concerns of the Caledonian Sleeper staff have not been honoured and the failure of Serco to come up with any serious progress in key talks yet again this week leaves us with no choice but to go ahead with our industrial action exactly as planned.
“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, and the shutdown of the service, is entirely Serco’s fault and the public will understand that. Everyone knows that when it comes to failure they are global specialists.
“The union remains available for genuine and serious talks but the ball is now firmly in Serco’s court.”
Caledonian Sleeper staff will join picket lines on Sunday and Monday evenings at London Euston, Glasgow, Edinburgh Waverley, Fort William, Aberdeen and Inverness stations.
A statement from Serco said: “We have been advised by the Rail, Maritime and Transport union (RMT) that their members intend to take strike action on Caledonian Sleeper services next week.
“As a result, we can confirm that all of our services departing on Sunday September 29 and Monday September 30 will be cancelled.
“We apologise to all of our affected guests for the inconvenience this will undoubtedly cause.
“We are in the process of arranging alternative transportation with other train operators. We will confirm the details of this as soon as we can.
“We will, of course, be processing refunds for all affected guests.”
The Caledonian Sleeper unveiled a new fleet of trains earlier this year, built at a cost of £150 million and offering double beds and en-suite bathrooms for guests making the journey between Scotland and London. Tickets are priced from £45 for seats to more than £300 for a superior double room.