London's Mayor appeared to apply the brakes to the idea of driverless trains operating on parts of the Tube.
Sadiq Khan said risking the safety of Londoners was 'the height of recklessness'.
Four years ago former London mayor Boris Johnson unveiled the first new-look driverless trains which were due to enter service on the Piccadilly Line in 2022.
At the time the RMT union said it was 'deeply concerned' about the move to driverless trains but Mr Johnson denied the move to phase out drivers would lead to job losses.
Today Sadiq Khan cast count on London Underground's driverless future.