Caledonian Sleeper train service workers have overwhelmingly voted in favour of a strike due to ‘intolerable pressure and working conditions’.

RMT union, which represents Caledonian Sleeper staff, said that the workers voted for strike action, as well as for ‘action short of a strike’.

Members voted by more than ten to one for both actions in a turnout of more than 80%.

Operated by Serco, Caledonian Sleeper is an overnight train service that runs between London and Scotland. In April, Caledonian Sleeper introduced new trains service.

According to RMT, staff morale plummeted following the introduction of new vehicles, with employees suffering from workplace stress and mental health issues.

Additionally, the union said that inadequate staffing levels, insufficient training and unresponsive management led to a complete breakdown of industrial relations.

The union’s executive will assess the results and decide subsequent steps.

RMT general secretary Mick Cash said: “Our members on the Caledonian Sleeper are sick and tired of paying the personal price for the botched introduction of the new fleet and that is why they have delivered this overwhelming vote for action.

“It is time for SERCO to wake up and take note of the appalling working conditions their mismanagement has lumped on their staff and to take action to resolve this dispute.”

Following the vote, Serco Caledonian Sleeper expressed its disappointment over the results.

Serco managing director for Caledonian Sleeper Ryan Flaherty said: “I believe we have shown a real commitment to dealing with the issues the RMT has raised and indeed there was an acceptance on all sides that progress was being made.

“We remain open and willing to engage in further talks to avoid industrial action and are fully committed to delivering the best possible service to guests.”