London Underground workers are to stage two strikes starting from next Sunday.
The action, over jobs and Tube ticket office closures, will see workers walk off the job for 16 hours from February 5.
The second strike, for 15 hours, is due to take place the following Tuesday, February 7, the RMT Union said on Friday.
The walkout follows a 24-hour Tube strike that occurred from 9pm Wednesday on the Central, Waterloo & City lines.
Mick Cash, of the RMT union said that “strenuous efforts” had been made to prevent the earlier walkouts, but “the door has been slammed in our faces.”
That action followed strikes on January 9 that led to authorities having to evacuate Clapham Junction station due to overcrowding.
Underground workers had launched a 24-hour strike at 6pm the previous night over a long-running dispute over ticket office closures which unions claim have cost more than 800 jobs.