STRIKES by London Underground drivers are to go ahead after last-ditch talks on Monday failed to resolve a dispute over the working week.

Members of the Rail, Maritime and Transport union (RMT) will walk out on Tuesday and Thursday, causing huge disruption to Tube services.

The two sides met for several hours on Monday but the talks ended without any resolution.

Transport for London (TfL) said that during the strike action no service is expected on the Circle line, Piccadilly line, the Metropolitan line between Baker Street and Aldgate, and the Central line between White City and Liverpool Street.

Services are expected across all other Tube lines on both days, but there will be disruption to journeys and service levels will vary across the London Underground network.

On both days, there will be limited service before 6.30am and customers are advised to complete their journeys by 9pm.

Normal service is expected on Wednesday and Friday.

The conciliation service Acas was involved in today’s talks.

The union is opposed to a new four-day week because of the impact on the length of shifts and other issues.

An RMT spokesperson said: “Despite our best efforts in Acas talks, TfL have failed to provide assurances on our members’ deeply held concerns around fatigue, reduced flexibility, shift lengths and the impact these proposals could have in a safety-critical role like Tube driving.

“We remain available for meaningful talks, but strike action tomorrow will now go ahead.”

TfL has said it would never compromise safety, adding that the new shift system was voluntary.