Strike action on the Bakerloo Line is due to go ahead, causing travel misery for passengers.
Members of the RMT Union working as drivers on the Bakerloo line will walk out for 24 hours at noon on Friday and again from noon on Sunday in a dispute over timetable changes.
The union said it had tried to make progress in talks at the conciliation service ACAS, accusing London Underground of failing to come up with a plan to deal with the issues.
London Underground said passengers should complete journeys on the Bakerloo line by 10am on Friday and there is likely to be little or no service until Monday evening, with delays to any service that is operating.
The Circle, District, Hammersmith & City and Metropolitan lines will also be closed in central London this weekend for testing of the new signalling system that will "hugely" increase capacity on the lines once completed.
The Northern line will also be closed between Moorgate and Kennington due to work on the Bank station upgrade.