Caledonian Sleeper services have been cancelled this weekend with planned strike action set to go ahead.

The Rail, Maritime and Transport Union (RMT) has condemned what it called operator Serco’s “pig-headed approach” and “blank refusal to engage in serious talks over the fundamental issues of fatigue and safety”.

The union has previously claimed rail bosses have not provided enough berths for rest periods, and members will now go ahead with two 48-hour walkouts as well as action short of a strike.

Previously, Serco said the plans for industrial action are “extremely disappointing” and claimed to have “done everything possible to provide staff with rest areas on board”.

All hosts and team leaders have been instructed not to book on for shifts from 5.30pm on Sunday to 5.30pm on Tuesday, and from 5.30pm on Sunday October 11 to 5.30pm on Tuesday October 13.

RMT general secretary Mick Cash said on Thursday: “It is appalling that Serco have tossed away the opportunity to resolve this dispute and that failure on the company’s part leaves them wholly responsible for the cancellation of services.

“RMT members on Serco Caledonian Sleeper are absolutely determined to seek justice in this dispute and I know that this will be displayed by full support across the service for this industrial action.

“We had a chance to broker a settlement yesterday but Serco have blown it.

“A clear message has been sent to management by their staff and it is now time for the Serco management to respond in a meaningful and positive way to the serious safety issues at the heart of this dispute.‎”

Members have also been instructed not to undertake any rest day working, higher grade duties or voluntary overtime between the evening of October 6 and October 11, and from 5.31pm on October 13 until further notice.

The overnight service between London and Scotland is operated by Serco on behalf of Transport Scotland.

A statement on the Caledonian Sleeper website says: “Due to the strike action by RMT members, all Caledonian Sleeper services will be cancelled on Sunday 4th and Monday 5th October 2020.

“All guests who have booked directly with Caledonian Sleeper will be contacted and receive an automatic refund to the card that was used to make the reservation.

“These refunds shall be processed by Friday 2nd October and can take up to five working days to show on the account. If you have booked your travel through a third party please contact them directly to arrange a refund.

“We apologise for the inconvenience this will undoubtedly cause.”

For the following weekend, October 11 and 12, the site adds: “These dates may also be affected by strike action by RMT.

“Whilst we remain in discussions with them to try and avoid a strike, we need to advise you that if it does go ahead, all of our services departing on Sunday 11th and Monday 12th October 2020 will be cancelled.

“If we do need to cancel services on these dates we shall make contact with guests who we have contact information for, and advise guests to check back to this page prior to travel.”

The company has also been contacted for comment.