South Western Railway (SWR) has confirmed two further dates for strike action in a long-running dispute over the role of guards on trains.
Members of the Rail, Maritime and Transport (RMT) union will walk out between 10:00 GMT on 9 March and 09:59 on 10 March.
They plan to strike again between 10:00 on 12 March and 09:59 on 13 March.
It is the sixth time the operator's staff have voted for industrial action in the past two-and-a-half years.
The company operates routes between London Waterloo, Reading, Bristol, Exeter, Weymouth and Portsmouth, as well as on the Isle of Wight.
The most recent strike, which lasted for 27 days in December, disrupted 600,000 passenger journeys each day.
Mick Cash, RMT's general secretary, said the union's members had been left with "no choice" but to take industrial action again and praised workers' "incredible amount of solidarity" during the dispute.
He added: "We are appalled by management's bullying and harassment tactics in their attempt to get our members to return to work.
"The company's constant barrage of lengthy letters every time our guard members take legal and legitimate industrial action is intimidating, degrading, humiliating and offensive."
SWR, which is introducing new trains that allow drivers to operate the doors instead of guards, said the union should be "talking, not striking".
"We have guaranteed to keep a guard on every train, but it is vital that we use the most efficient means of dispatch when we introduce our new trains so that we can deliver the improved performance our customers so desperately need," a spokesman said.