The Caledonian Sleeper's £150m revamp will offer a "new standard in overnight travel", it is claimed.

Customers have been told they can expect a "hotel-like" experience in the new carriages.

A fleet of 75 are being constructed in Spain as part of the upgrade to the overnight service between Scotland and London.

Included in the upgrade will be en suite rooms, key card entry systems, bespoke comfort seats designed for long journeys, upgraded panels for phone and gadget charging and WiFi throughout the train.

The trains will also offer a range of accommodation options including twin or single classic rooms, twin or single club rooms with en suite and a double bed with en suite.

A new website has been launched to give customers a glimpse inside the new project as it is being built.

Newtrains.sleeper.scot will provide details of the trains ahead of their phased introduction to service from spring 2018.

The sleeper train is run by public service provider Serco, which promised major improvements when it purchased the franchise in 2015, part-funded by the Scottish Government.

The introduction of the new trains will be the culmination of a wide range of improvements and investment in the service.

Peter Strachan, chairman of Caledonian Sleeper, said: "Travelling with the Caledonian Sleeper is a wonderful experience and the new train fleet being introduced will offer a new standard in overnight travel.

"This website is where members of the public can see the latest news on the trains and discover the exciting things we have in store.

"The Sleeper is already a fantastic way to travel and the new trains will improve the service dramatically."

He added: "Providing comfort and convenience, the Sleeper allows for plenty of time for a full day of work or play, before transporting you to and from the destinations we serve without the hassle of flying.

"The Sleeper offers great value for money compared to other travel and accommodation options and combined with the new train accommodation, will give guests the journey of a night-time."

Highlights include a new guest service centre in Inverness as well as new uniforms, toiletries and food and beverage offer, the vast majority of which is from Scottish suppliers.

Ticketing will also been improved, with new tickets for families travelling together, the introduction of electronic ticketing and enhanced online functionality for regular guests.

Prices for the new services are yet to be confirmed.