Northern has responded to the start of RMT’s ballot of Northern conductors.
A spokesman for Northern said: "Our focus is on protecting the jobs and pay of our people as we work to implement a modernisation programme that will maintain high safety standards, deliver better journeys and improve customer service. We therefore believe RMT is very premature in starting a ballot of conductors to vote for strike action.
“We want to agree a constructive resolution to this dispute and to continue the discussions we have started with RMT. Should any strike action go ahead, we want to reassure our customers that we are preparing plans to keep them moving.”