The concept, dubbed Breeze, involves reengineering class 321 EMUs originally built by British Rail Engineering Limited in 1988-1991. Most of the fleet of 117 trains is due to come off lease within the next few years due to the delivery of new fleets.

Alstom and Eversholt Rail say they are working closely with industry stakeholders to develop the business cases and evaluate detailed introduction plans for both the trains and fuelling infrastructure.

An initial engineering study has been completed and the design concept has been finalised.

The Breeze conversions will be carried out by Alstom at the company’s Widnes facility in northwest England and the manufacturer says the first completed train could be in operation by 2022.

Alstom has previously said the trains will have a range of 1000km and a maximum speed of 140km/h.