Currently, only 3% of mail is transported by train.

A Royal Mail spokesperson explained the rationale behind the change, and said: “Royal Mail will continue to use rail services to transport mail across the country however our own freight trains are at the end of their operational lives.

“The trains are almost 30 years old and it is increasingly difficult to secure parts for maintenance and the routes we need to meet our service requirements.”

The postal operator said that over the coming months it would cease to operate its own trains, but would continue to use a mix of rail, road and air “to transport mail to all corners of the UK”.

It claimed reliability and cost-effectiveness would be improved, and the move would also help the group with its environmental goals.

No job losses are planned, with related Royal Mail employees expected to be redeployed.

The additional transport workload will create more than 30 full-time driving jobs.

In a statement, the CEO of rail freight specialist DB Cargo UK, which provides services to Royal Mail flagged the increasing costs of electric traction (EC4T) as being a factor behind the decision.

Andrea Rossi said the decision represented “a major U-turn by Royal Mail, which had previously committed publicly that it would increase its use of rail freight to help meet its own Net Zero targets”.

“So this is not a decision against DB Cargo UK, but one against the economics of rail freight as a mode of transport.

“As a result, we will now be seeking urgent talks with the new Labour Government, policymakers and other key industry stakeholders, to see what more can be done to level the playing field between rail freight and the heavily subsidised road haulage sector.”

Royal Mail has also reiterated its commitments to achieving Net Zero by 2040.

The group currently has around 5,000 electric vans in operation and has deployed over 10m litres of HVO (Hydrotreated Vegetable Oil) biofuel since June 2023.

The move will be “broadly neutral” in terms of CO2e emissions.