Passengers on the London Underground are being warned to expect disruption between 19 and 22 May after the RMT union confirmed strike action in an ongoing dispute over proposed voluntary four-day working arrangements for Tube drivers.

Transport for London said services would continue to operate on most lines, although reduced timetables and altered operating hours are expected throughout the four days.

No service is expected on the Circle line or Piccadilly line during the strikes. The Metropolitan line is also expected to be suspended between Baker Street and Aldgate, while the Central line is not expected to run between White City and Liverpool Street.

On Tuesday, 19 May, and Thursday, 21 May, normal services are expected to operate until mid-morning, after which disruption increases, and services finish earlier than usual. On Wednesday, 20 May, and Friday, 22 May, disruption is expected from the start of service, with trains beginning later than normal, before improving from midday into the afternoon and evening.

The dispute centres on concerns raised by the RMT over plans to introduce a compressed four-day week, along with fatigue concerns. Transport for London said many of the union’s objections could still be resolved through further negotiations involving other trade unions, but warned that the planned industrial action would nonetheless affect services across the network.

Further information on the strikes can be found online.

“It is disappointing that the RMT is planning this strike action despite our best efforts to resolve this dispute. We have been clear that our proposals for a four-day week are designed to improve work-life balance and are entirely voluntary. Any Tube driver who doesn’t wish to opt in to the new, four-day working pattern and associated changes to working arrangements can remain on a five-day working pattern. We have also said many times in discussions that we believe the majority of the issues that have been raised would be resolved with more detailed work.

“A significant number of drivers have indicated that they want us to progress plans for the pilot of this new working pattern on the Bakerloo line, and it would deliver benefits both for our colleagues and our customers. We urge the RMT to work with us so we can resolve this dispute. In the meantime, we are asking customers to check before they travel and allow plenty of extra time for their journeys.”

Claire Mann, TfL’s Chief Operating Officer