A BRAND new £100 million fleet of sleeper trains to run between Scotland and London has been delayed for a second time.

They were initially due to use the new carriages in April, but the company blamed production delays with Spanish-based manufacturer CAF.

The rollout was postponed until later this month, but operator Serco yesterday announced another delay in delivery of the fleet to operate the Caledonian Sleeper service.

CAF was also responsible for building the trams currently running on Edinburgh’s city network.

Serco said 35 of the luxury carriages - which include double beds and en suite showers - were in the “final build stages,” adding they would be “delivered in the coming weeks”.

It added testing and gaining “regulatory approval” for the new carriages was “time-consuming and complex” and blamed this process as the main cause of the delay until next Spring.

It is understood as many as 1,800 passengers were booked on the fleet’s journeys between October and March, but the company has said customers will be offered a full refund or opportunity to rebook their travel.

Fees for private ensuite double rooms start from £200 per passenger, while single “club” rooms start from £125.

New features include a hotel-style door card entry system, charging points and wi-fi.

Ryan Flaherty, Serco’s Managing Director at Caledonian Sleeper, said: “We are sorry that we will not be able to launch the service this Autumn, and understand that customers who wanted to travel on them in 2018 will be disappointed.

“But with five different accommodation types, as well as on board catering, dining and shower facilities, this is the most complex introduction of new rolling stock ever undertaken in the UK, and we are determined to get it right.”

He added: “The new sleeper carriages are absolutely superb, and will transform the experience of travelling by train between Scotland and England.”

The launch of the Lowland service between London, Glasgow and Edinburgh will go live first, with the Highland service to Fort William, Inverness and Aberdeen coming at a later date.

The introduction of new trains will be the culmination of a wide range of improvements and investment in Caledonian Sleeper since Serco took over the franchise on behalf of the Scottish Government in April 2015.

These have had a significant impact on the service and after years of decline, the number of customer journeys has increased by 21%.

The fleet is currently being constructed in Spain, part funded by a capital grant from Scottish Ministers of £60m and will be the first sleeper trains to be introduced to the UK for over 35 years.

Transport Secretary Michael Matheson has written to Serco expressing “disappointment” with the delay after “significant” public investment in the new fleet.

Tickets for the new service will see Comfort Seats starting from £45, Classic Rooms starting from £85 per person, Club Rooms from £125 per person and Suites from £200 per person.

En-suite toilets in business class berths, wifi and electricity supplies in every carriage, and secure luggage storage for all passengers were among facilities demanded as the Caledonian Sleeper prepares to undergo its first major overhaul in more than 30 years.

The Caledonian Sleeper is the longest passenger train in the UK, carrying some 270,000 passengers a year, six nights a week, between London Euston and Aberdeen, Edinburgh, Fort William, Glasgow and Inverness.

Ambitious plans to modernise it came less than two years after fears that the service - which operates at an annual loss of about £5m - might be scrapped. The news outraged high-profile fans including many politicians commuting between Westminster and Scotland, as well as Glasgow-based broadcaster Kirsty Wark.

Scottish Labour’s Shadow Cabinet Secretary for Rural Economy, Connectivity and Transport, Colin Smyth MSP said: “The Caledonian Sleeper could be the pride of Scotland’s railways - but once again we see a private rail provider failing passengers. New carriages are vital to the relaunch of the service and their delay will be a serious disappointment to passengers, many of whom have already made bookings.

“Under the franchise agreement, these new carriages should have been in place in April, that was then delayed until October - and now we learn they won’t be delivered until spring next year. Michael Matheson is right to demand a firm date for their introduction from Serco, but he should also be applying far greater pressure on the company to establish what has gone wrong in the first place”.