Eurostar rail workers are to go on strike over two weekends in August in a dispute over work/life balance.
Members of the Rail, Maritime and Transport union voted in favour of action that will see them take seven days of industrial action.
Workers will walk out:
from 0.01am on Friday August 12 until 11.59pm on Monday August 15
for three days over the Bank Holiday weekend from August 27
Eurostar said it will try and run as normal a service as possible and will notify all affected passengers in advance of "small changes" to the timetable.
It is the latest industrial dispute to break out on the railways, affecting thousands of passengers.
The union has also announced a vote for action on Virgin Trains East Coast over jobs.
Around 80 train managers are said to be involved in the long-running Eurostar dispute, claiming agreements over shift work and unsocial hours have been "repeatedly undermined".
The RMT has accused Eurostar of failing to honour an agreement from 2008 which looked to guarantee the drivers a quality of life beyond work.
The union's general secretary Mick Cash called on Eurostar to come to the negotiating table with a set of proposals to redress the matter.
Our train manager members at Eurostar have a heavy commitment to shift work and unsocial hours and are sick and tired of the company's failure to honour agreements.
Transport Secretary Chris Grayling condemned the action and said it was part of a wider union agenda in the face of "progress" in the railways.
A Eurostar spokesman said it would notify affected passengers on timetable changes being made to ensure all can still travel on their booked days.
The spokesman added the company's "focus" has been on "seeking a joint resolution whilst planning to provide a good service for our customers".