The RMT has announced that two separate days of strike action will be taken in the run-up to the Easter holiday.
Staff at Northern Rail will walk out from midnight on Monday, March 26 and then again from midnight on Thursday, March 29 - ahead of Good Friday on March 30.
This latest lot of strike action will mark the 16th and 17th time staff have walked out in the ongoing dispute.
RMT General Secretary Mick Cash said the dispute was over 'putting the safety of the travelling public before the profits of the private train companies'.
He added: "It is frankly ludicrous that we have been able to negotiate long-term arrangements in Scotland and Wales that protect the guards and passenger safety but we are being denied the same opportunities with rail companies in England.
“Theresa May and Chris Grayling are happy to stand aside and cheer on overseas rail companies that rip-off the British passenger with eye-watering far increases to subsidise their domestic transport operations while throwing the guards off our trains. If it’s good enough for Wales and Scotland to put safety first then it’s good enough for the rest of the UK.
“RMT remains ready for the tripartite talks we have suggested.”
But a spokesman for Northern Rail said they were bringing about the 'biggest improvement to local rail services for a generation.
They continued: We have a commitment to introduce Driver Controlled Operation on parts of the Northern network. This is why we want to have meaningful talks with RMT to explore future staffing options on trains and stations. In some areas we may choose to staff more stations and in others, it could make sense to have more customer support on trains. These are the important, constructive discussions we want to have with RMT.
They added: "We are unable to predict how long RMT’s dispute will last. We have again proposed to RMT that they set aside what appears to be a co-ordinated campaign in return for assurances over jobs and pay, and exploring with us what future roles will look like. We are frustrated at the lack of progress in talks as business and communities are behind our modernisation and investment plans and we want RMT to back this too.
"This is the biggest improvement to local rail services for a generation, including new trains, more services and better stations. This will mean changes to roles to provide more support to customers, in addition to protecting jobs and pay for existing conductors - but those guarantees cannot last forever."