Southern Rail bosses and the RMT Union say they are both open to peace talks ahead of planned two-day strike on the network next month (7 and 8 September 2016). But the parties, who are in dispute over the future role of rail guards, cannot decide on the pre-conditions to the negotiations due to take place at mitigation service Acas.

Mick Cash, the general secretary of the RMT, claims that a "major obstacle" to progress has been Govia Thameslink Railway (GTR) vow to press on with its modernisation plans, which would see drivers close train doors in conjunction CCTV.

"We would call on the company to row back, get back round the table and allow talks to take place without preconditions and without the immediate threat to their safety critical role hanging over our members' heads," Cash said.

GTR, meanwhile, wants the union to get back round the table to find a solution to their "futile" industrial action. "The fact is we are creating good jobs – jobs that attracted over 850 enquiries within 24 hours of being advertised, with good terms and conditions," said Alex Foulds, passenger services director for Southern.

"We've made a fair and comprehensive offer and perhaps it's an offer that the RMT should put to their members to consider.

He added: "We have an open mind to all options that lead to the implementation of our proposal to introduce the new on-board roles on our trains and enhance the services we want to provide our customers. Enough is enough. Let's stop the strikes and settle it."

The latest back and forth between the RMT and GTR comes after Southern customers faced disruption amid a five-day-long walkout, which was suspended after third strike by the RMT.