Three classes of travel are to be offered on Britain's domestic railway for the first time in decades.

Avanti West Coast, which replaced Virgin Trains on the West Coast Main Line on Sunday, is developing a premium economy-style offering.

Trains running on Britain's mainline railway currently only have standard class or first class.

But passengers who want an upgrade without buying the most expensive tickets will be able to obtain an enhanced service once Avanti West Coast finalises its plans.

The extra class is likely to be introduced once the Pendolino carriages the firm inherited from Virgin Trains are refurbished. The first revamped train is expected to return to service by early autumn 2020.

It is not known how much the middle tier of fares would cost.

Avanti managing director Phil Whittingham, who previously held the same role at Virgin Trains, said: "We know there is going to be three classes. It is going to be a first class, a premium economy-type style and economy."

He said passengers in premium economy could be entitled to "the bigger seat, better wi-fi and snacks rather than a meal".

Matthew Gregory, chief executive of FirstGroup, which joint-owns the franchise with Italian firm Trenitalia, said the change in policy is "about balancing and being flexible within the train".

He went on: "Obviously first class can be quite expensive, so there are different price points between standard class and first class and it is about seeing if we can offer a more flexible offering that suits more price points."

Third-class rail travel was abolished in Britain in 1956 and renamed second class before later being branded standard class.