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

The Rail, Maritime and Transport Union (RMT) has confirmed that the strikes will go ahead after talks broke down.

RMT condemned what it called operator opeartor 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.

Four days of disruption are expected this month for passengers using the overnight Scotland to London train service after RMT union members were balloted on industrial action and action short of strike.

RMT said there was an "overwhelming ballot result" where members showed a "clear desire" to take industrial action against [operator] Serco's "lack of concern for member's safety and wellbeing" and the company's refusal to negotiate with their union.

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”.

It is the latest issue to hit the service after the Scottish transport secretary said in January that faults with the fleet will take another two months to fix.

RMT said the action was sparked after Serco Caledonian Sleeper continued to provide insufficient berths for rest periods and the company's inability to address the fatigue experienced by staff.

All hosts and team leaders have now 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: “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.

READ MORE: Caledonian Sleeper operator criticises plans for 48-hour strikes over safety fears

“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.”

Serco Caledonian Sleeper launched its new £150 million fleet on the lowlander route between London and Glasgow/Edinburgh in April, last year.

But it was beset with difficulties including delays botched reservations, broken air conditioning, food shortages and a fault that led to emergency exit windows being locked shut.

In October the independent regulator, the Office of Rail and Road revealed that the Caledonian Sleeper has the worst passenger complaint rate in the whole of the UK.

ORR data for the first quarter of this year revealed that the luxury sleeper service between London and Scotland received 206 complaints per every 100,000 journeys, up by 67% on the previous year.

Ryan Flaherty, Serco’s managing director for Caledonian Sleeper, said the group remains committed to finding a resolution to the dispute.

He added: “We are deeply disappointed and frustrated that this action is going ahead at a time when everyone’s focus should be on maintaining vital Scottish transport links.

“This action is completely unjustified. Less than a third of our workforce voted in favour of industrial action and our employees working on board the trains have received full pay during the pandemic, despite working reduced hours.

“When some of our employees raised concerns about fatigue, we brought in an independent fatigue specialist to conduct a fatigue risk assessment on our services.

“He has completed his report, which clearly concludes that not only is Caledonian Sleeper operating within all regulations, but that only two people raised the issue of additional rooms for hosts, which has become the RMT’s main demand.

“It is therefore extremely disappointing that we currently remain in a position of being unable to resolve the dispute on a subject that only two people raised during the fatigue risk assessment process.

“Despite the findings of the report and our offer to continue to engage with (conciliation service) Acas, which still stands, the RMT has refused to engage in negotiations to bring this dispute to a resolution, unless their unreasonable demands for rooms for every host are met.”