Workers on Southern Railway are to stage a fresh strike in the bitter dispute over staffing and the role of conductors.
Members of the RMT union will walk out for 24 hours on April 4 making it the 31st day of strike action since the row began almost a year ago.
The announcement was made as members of the drivers' union Aslef started voting on a deal aimed at resolving their dispute over driver-only trains.
The RMT said it continued to press the company for a firm date for talks over the future role of the guard.
The union said that it would reconsider its action to allow for talks to take place.