Face masks are set to stay compulsory on the London Underground and buses under plans announced by the capital’s Mayor, Sadiq Khan.

Mr Khan has asked Transport for London (TfL) to retain face coverings as a mandatory measure after next Monday, when national guidance changes.

This week, Boris Johnson confirmed that, from July 19, the legal requirement to wear a mask will end but they will be "expected and recommended" in crowded and enclosed spaces such as public transport.

Mr Khan has gone a step further and drawn up proposals for their use to be made a "condition of carriage" on all TfL tubes, buses, trams, overground and automated light metro trains.

The Labour Mayor, who is the chairman of TfL, has also instructed TfL to keep masks mandatory in taxis and Ubers. TfL must now conduct an equality impact assessment of the plan, but it is expected to go ahead.

Labour has petitioned the Government to keep masks mandatory on transport and in shops, theatres and cinemas, rather than scrapping the legal requirements at step four of the roadmap.

Face masks poll

Conditions of carriage are contractual conditions between passengers and TfL. Existing conditions include not consuming alcohol, smoking or vaping.

Trained enforcement officers will continue to tour London’s transport network to ensure that passengers are wearing masks as well as carrying the correct ticket.

Sources familiar with the enforcement of the current mask rules say compliance has been high. However, trade unions have warned that frontline staff could face disputes with passengers when trying to enforce masks once the England-wide guidance changes.

It emerged this week that MPs will be free to make their own choice over whether to wear a mask, but it will remain compulsory for Commons staff. On Tuesday, the FDA union, which represents senior civil servants, said it would name and shame MPs who refused to wear face coverings.