Most e-bikes will be banned across the London Underground and other Transport for London services, after growing safety concerns over igniting batteries.

Only folding e-bikes, which are less likely to have been modified and are deemed less of a safety risk, will be permitted on the London Underground, Overground, Elizabeth Line and DLR trains from 31 March.

Transport for London (TfL) said the ban was to ensure the safety of customers and staff, in the wake of union threats to strike after a series of fires.

Last month, an e-bike exploded into flames on a London Underground platform at Rayners Lane, an incident the train drivers’ union Aslef said could have caused mass casualties.

TfL said it had been working closely with the London fire brigade on a comprehensive review of the safety of e-bikes. While it said most were safe, there had been a small number of incidents where non-foldable e-bikes had caught fire on its network.

Bicycles converted to e-bikes using conversion kits are regarded by TfL as a greater fire risk than purpose-built e-bikes, but it said that as it was difficult to differentiate between models a general ban was necessary until improved safety measures were in place.

All non-folding bikes are already banned on buses or trams. E-scooters are also banned across TfL due to the fire risk.

An exception to the e-bike ban will be made for the new Silvertown tunnel cycle shuttle service, the Woolwich Ferry and other river boats.

TfL said it recognised the important role of e-bikes and micromobility for London and would keep the rules under review.

The mayor of London, Sadiq Khan, said: “The safety of Londoners is my top priority and, while most e-bikes are safe, there have been a small number of incidents where non-foldable e-bikes have caught fire on the transport system, which have caused me great concern.

“This is why, following a comprehensive review of the safety of e-bikes, TfL is banning all non-folding e-bikes on tube and rail services.”

Lilli Matson, TfL’s chief safety, health and environment officer, said the ban would “play a vital role in keeping our transport system safe for everyone, and we continue to work with partners in government and beyond to improve e-bike safety”.

Aslef, which had called for action, said they would prefer a full ban, but that foldable bikes were safer and less obstructive in emergencies.

Finn Brennan, Aslef’s organiser on the underground, said: “We welcome this announcement as a step in the right direction.”

There has been no update yet on the recent removal of book exchanges on London Underground as a perceived fire risk – a move that Khan said was “ridiculous” and pledged to overturn.