Rail union RMT has confirmed that further strike action will be taking place on Arriva Rail North.
Trains run by Northern will be affected on May 24 and 26.
The dispute is over the proposed introduction of driver-only trains on the network.
All Arriva Rail North conductors, conductor instructors and train driver members are instructed not to book on for any shifts on Thursday May 24 and Saturday May 26.
RMT general secretary Mick Cash said: “It is a tribute to the determination and professionalism of RMT members on Arriva Rail North that they have remained rock solid for over a year now in what is a battle to put public safety before private profit.”
Northern will run as many services as possible on the two affected dates.