London Underground drivers are to stage two 24-hour strikes in a long-running dispute over terms and conditions.
Members of Aslef will walk out on April 8 and May 4, threatening travel misery across the capital.
Finn Brennan, the union’s organiser on LU, said the company had failed to give assurances that changes to terms and conditions will not be imposed without agreement.
He said: “Despite a previous commitment to withdraw plans for massive changes to drivers’ working conditions, London Underground management has established a full-time team of managers preparing to impose their plans.
“They want drivers to work longer shifts, spending up to 25% more time in the cab, and to remove all current working agreements in the name of flexibility and efficiency.
“Everyone knows what these management buzz words really mean. It’s about getting people to work harder and longer for less.”
Aslef drivers have voted by 98% in favour of strikes.
They went on strike a year ago in the same dispute.
A Transport for London spokesperson said: “We have been in long-term discussions with our trade union colleagues on how to modernise procedures and processes on London Underground to improve the experience both for staff and customers.
“We have no plans to impose these changes and have committed to no-one losing their job as part of these changes, and we have engaged with our unions to demonstrate that no change will be made that compromises our steadfast commitment to safety on the Tube network.
“We urge Aslef to continue discussions with us so that disruption for Londoners can be averted.”