"Talks with London Underground have proved to be positive and focused and as a result we have been able to make enough significant progress to allow us to suspend the strike action in both disputes that was scheduled for tomorrow evening," RMT General Secretary Mick Cash said in a statement.
Cash attributed the success of negotiations to "the strength and resilience of our members in the workplace backed up by a determined and professional negotiating team."
The action was related to two separate disputes involving drivers. The union stated that all objectives in the Piccadilly Line dispute had been achieved, with the help of the Advisory, Conciliation and Arbitration Service, and that the union was looking to conduct further talks to reach an agreement on the Hammersmith and City Line.