The union at the centre of a long-running row over rail safety has announced another 24-hour strike affecting Wigan.
RMT members employed by Northern, which runs services through both the town centre's stations, will not be working on Saturday July 21.
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The walk-out is the latest in a rolling programme of industrial action over plans to axe the guards on trains, which the union says is vital for passenger safety and access.
The union once again slammed train operator Northern, the trading name of Arriva Rail North, and its owner Arriva over how the dispute has been handled.
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. The next phase of action will take place two weeks on Saturday as the company refuses point blank to engage in talks.
"RMT is angry and frustrated that while we are making some progress in discussions in similar safety disputes Arriva Rail North refuses point blank to engage with the union in any meaningful fashion. That is a disgrace and speaks volumes about the attitude of this company.
"Northern wants to run nearly half a million trains a year without a safety critical guard on board in a move that would wreck both safety and access to services and they should listen to their front-line staff and pull back from that plan immediately.
“We have seen repeatedly in recent weeks that Arriva are not capable of running a railway and have chosen to declare war on passengers and staff alike in the drive for increased profits while safety, access and reliability are left to rot.
"RMT has agreed arrangements in Wales and Scotland that enshrine the guard guarantee. If it's good enough for Wales and Scotland to have safe rail services it should be good enough for the rest of Britain.
“We thank the public for their support and understanding throughout this dispute over rail safety and access and the union remains ready for talks.”