London Trams passengers, including those travelling to the Wimbledon tennis tournament, are being urged to consider alternative routes because of strikes by maintenance workers.
Members of Unite will walk out from June 30 to July 8 and again from July 11 to 15 in a dispute over pay.
Transport for London (TfL) said it expected a reduced and disrupted service on the whole of the London Trams network for some of these days.
Passengers were advised to complete their journey by 6pm on strike days.
TfL said: “Where possible, customers should consider walking and cycling for local journeys. London Buses and London Overground are expected to operate as normal but could be busier than normal.”
Navid Golshan, general manager for London Trams, said: “We urge Unite to work with us to find a resolution and call these strikes off.
“Customers planning to use London Trams services are encouraged to check before they travel, allow extra time for their journeys, and check the TfL website or the TfL Go app for the latest travel information.”
The workers first took strike action in March, saying they are paid up to £10,000 a year less than their colleagues on the London Underground, despite requiring the same qualifications and performing the same roles.
Unite general secretary Sharon Graham said: “TfL thinks it can employ these workers on the cheap and treat them as second-class employees.
“The situation is totally unacceptable and our members are absolutely right to take strike action. They have Unite’s unflinching support.”