Public transport campaigners have urged Royal Mail to transport post by rail after the company axed its fleet of mail trains last month.

Campaign for Better Transport (CBT) supporters delivered a giant postcard to the postal service’s head office in central London on Friday morning with the message “Mail belongs on rail”.

Royal Mail said in July its almost 30-year-old red freight trains were at the end of their operational lives and it would not purchase replacements.

The last journey by the fleet took place last month.

Royal Mail previously pledged to use other train services to transport mail.

It said it started a three-month trial with a commercial freight train operator earlier this month.

Royal Mail began running trains to transport post in 1830.

Thousands of people added their names to the CBT postcard, which was addressed to Royal Mail chairman Keith Williams.

Mr Williams holds the same position at Great British Railways Transition Team, which is working with the Government and the rail industry to prepare for planned widespread reform of the sector.

The text of the postcard read: “Mail and rail belong together: they have been working in concert, connecting communities for almost 200 years.

“It is therefore vital that Royal Mail and the Government work to increase the amount of mail delivered by train, not risk pushing more onto the roads.

“After a year of record-breaking global temperatures, any reduction in rail freight would be all the more disastrous, increasing carbon emissions, air pollution and traffic on our roads.

“With your roles at both Royal Mail and Great British Railways, you have a perfect opportunity to find a solution.”

CBT head of campaigns Michael Solomon Williams described Royal Mail’s decision to decommission its train fleet as “tragic” but insisted “this need not be the end of the line”.

He said: “Post is changing, not declining, and online parcel orders make the case for greener, faster deliveries, so Royal Mail should lead by example.

“It should reach out to the Government, which has professed its support for rail freight, and work with it to get deliveries back on track.”

Rail historian and broadcaster Christian Wolmar said mail has been carried by rail “profitably for both parties” for nearly 200 years.

He added: “A way must now be found to continue that symbiotic relationship.”

Andrea Rossi, chief executive of DB Cargo UK, which operated Royal Mail’s trains, said he was “deeply disappointed” at Royal Mail’s decision to “switch from rail to road-based logistics”.