The Royal Mail is testing the use of electric vans for postal rounds, as part of efforts to cut emissions.
The vans are refitted electric black taxi cabs. The design that is ultimately launched will probably be different.
The first van will be tested in Birmingham, with more to follow in Leeds, Derby, Edinburgh and Bristol.
Royal Mail, which is partnering with the London Electric Vehicle Company, plans to launch more later this year.
The 2.9 tonne (2,900kg) van will be charged at local post offices.
The battery will last for a typical postal round. It can also be extended if needs be to cope with longer, more remote locations.
There are currently 295 Royal Mail vans in operation, and the new electric fleet would complement rather than replace these.
Paul Gatti, fleet director at the Royal Mail, said: “As a company, we are committed to making changes to our operations that reduce our environmental impact whilst ensuring we continue to meet customer expectations.”
Some 24 other firms are also trialling the refitted black cabs.
Joerg Hofmann, chief executive of the London Electric Vehicle Company, said: “Royal Mail is one of the oldest postal services in the world, and like our London black cab is part of British history and culture. It is great that these two iconic brands are joining forces for this trial.”
He added that the trial would “test the vehicle’s ability to the full”.
Countries around the world are looking to cut the emissions from petrol and diesel-powered vehicles. Many have focused on vans and trucks because the larger vehicles are bigger polluters than cars.