Rail workers will launch a fresh wave of industrial action on Good Friday in the long-running disputes over the role of guards on trains, with no sign of any breakthrough to the deadlock.
Members of the Rail, Maritime and Transport union on South Western Railway (SWR) will refuse to work any rest days over the four day Easter break.
The action follows a strike on Arriva Rail North on Thursday over the same issue.
Five train operators are now embroiled in the dispute, which has been raging for almost two years when it began at Southern Railway.
SWR said in a message to passengers: "We're really sorry that once again, you are to be subjected to unnecessary industrial action by the RMT.
"We plan to run our full service on all four days and will do everything we can to minimise any effect this strike action may have. We do however advise you to check before you travel."
RMT general secretary Mick Cash said: "It is frankly disgraceful that South Western Railway continue to point-blank refuse to engage with the union in meaningful talks over their plans to run trains without a safety-critical guard on board.
"Instead, they continue to resort to the crudest possible attempts to threaten, bully and harass our members fighting to put public safety before private profit.
"It is the continuing intransigent attitude of the company which means that this latest phase of industrial action goes ahead over Easter in an effort to force them to see sense and to drive them back to the negotiating table for genuine and meaningful talks.
"We know that this action will have a serious impact on services and the responsibility for the disruption caused will be wholly down to South Western Railway and their pig-headed attitude."
SWR maintains it wants to reach a deal with the RMT over staffing.
:: A 48-hour RMT strike on London's Docklands Light Railway was ending on Friday morning after crippling services.
The union says there has been a breakdown of industrial relations on the DLR.