UNION chiefs should "engage in conversation", according to under-fire train boss David Brown.

The Northern chief executive said that the decision of officials at the Rail, Maritime and Transport Union (RMT) for three more days of strikes later this month is "really disappointing".

It comes after the union's general secretary, Mick Cash, hit out at the operator over plans to reduce the number of conductors on trains.

He said the strikes were a direct response to the introduction of driver-only operated services.

He added: "We have seen over the past fortnight that Northern is a company which has declared war on its passengers and staff alike. RMT will not stand aside while the threat to axe safety critical guards from Northern services remains central to the company's plans.

“This company has reduced the timetable to total chaos and the union will not allow them to slash the safety culture to ribbons in the same fashion."

Mr Cash pointed to agreements reached between the RMT and train services in Wales and Scotland as proof that the union is willing to negotiate.

Strike action is due to take place on June 19, 21 and 23, and Northern have warned that just 40 per cent of services could run.

Mr Brown said: "We’re not in dispute with the RMT, the RMT are in dispute with us, we would like to sit down and engage with them in conversation about the future role of the conductors and the onboard staff.

"At this point in time they have announced three more strikes which I think is really disappointing because it will impact on staff here that have to work those days and it will really impact on customers because there’s a lower level of service.

"We have been encouraging them to suspend that action and have a conversation with us about the future role of the conductor."

Northern bosses have now reached an agreement with other train companies that means that, until July 29, customers with tickets to travel on Northern will be able to travel on services provided by other rail operators if they are unable to complete their journey due to delays or cancellations.