Workers from two rail companies will go on strike next month as part of the continuing row over driver-only operated trains.
Arriva Rail North (Northern) and Merseyrail workers in the RMT union will walk out on 3 March.
The union says scrapping guards and introducing driver-only operated trains risks passenger safety.
But the rail companies have insisted the move is safe and already widely used.
The RMT said the dispute is "about putting the safety of the travelling public before the profits of the private train companies".
RMT general secretary Mick Cash said that "every single effort" made by the unions to negotiate with Northern and Merseyrail over safe operation and safe staffing "has been kicked back in our faces".
Merseyrail said it has "continually sought to reach a compromised solution".
Managing director Andy Heath said: "I would again urge our guards to reconsider their strike action at a time when we should really be in talks about how we can work together to give you clarity and security about your future, building on our commitment to guarantee you a job within our business.
"Talking is the only way that can be achieved."
Union members from the two train companies last walked out on three days in January, alongside workers from South Western Railway and Greater Anglia.
RMT members at South Western Railway will ban rest-day working for four days from Friday as part of the dispute, which also affects Southern and Greater Anglia.