The £362m procurement will be funded with the aid of a £337m grant from the British government, with Nexus providing the remaining £25m through its own budget.

The decision to launch the tendering process was approved by the North East Combined Authority leadership board on January 16. A periodic indicative notice for the procurement was published in the Official Journal of the European Union on January 25.

An information day for prospective bidders will be held in June, and Nexus expects to announce a shortlist of suppliers by the end of the summer. The winning bidder will be announced in 2019 and delivery of the new trains will start at the end of 2021.

Nexus is seeking 84 1.5Kv dc overhead trains to replace the current fleet of 90 trains supplied by Metro-Cammell in 1978-81.

The new trains will be equipped with air-conditioning, digital connectivity, and phone charging points. Linear seating will replace the lateral seating layout of the current fleet to create more space for passengers with wheelchairs, standing room, and luggage. Nexus says the seating layout has been chosen following extensive public consultation.

“The trains that we will buy will transform the reliability of the Metro system, as well as reducing energy usage and updating the experience of travelling by Metro,” says Nexus managing director Mr Tobyn Hugues. “We will also future-proof them so that they have the capability of serving more destinations on a wider network in the future.”

The contract will include a train service agreement covering maintenance of both the existing and future fleets. This will come into effect in 2020 and will run for 35 years with breakpoints, the first of which is likely to be after 10 years.

The winning bidder will also construct a new depot on the site of the current facility at Gosforth, which dates from the 1920s and is described by Nexus as “not fit for purpose.”