Peace talks between Southern rail and the RMT union have broken prematurely without any resolution.
The talks at mediation service Acas were meant to resolve the ongoing dispute over Southern's plans to use driver-only-operations on the network.
The breakdown of talks means that there could still be further strike action on Southern despite previous positive steps to resolve the dispute.
RMT General Secretary Mick Cash said: "RMT entered today's talks in good faith but it soon became clear that the only thing Southern were interested in was bulldozing through driver only operation further and faster with safety and access to services not even on their agenda. That pig-headed attitude has today wrecked the talks process".
"Not only have Southern refused point blank to give a guarantee on a second safety critical member of staff but the company have also made it clear that the deal set up by the TUC in the drivers' dispute is even worse than we first expected and gives Southern a free run to kick the legs from under our members who have fought for nearly a year on the principles of safety and access".
"RMT's negotiating team is furious at the way this union and its members have been treated. This is dire news not just for staff but for passengers who rightly demand a safe, reliable and accessible service. I will now take a full report back to the unions exectutive."
Nick Brown, Chief Operating Officer of GTR, Southern's parent, said: "We came to today's meeting hopeful we could find a way forward to end the RMT's dispute and we're saddened it's ended so prematurely. The travelling public will find the union's obstinate refusal to engage in meaningful and constructive talks disappointing, disheartening and increasingly destructive".
"Over the past year the RMT has had 28 days of strikes on this one issue, we've seen in excess 20,000 trains cancelled as a result, thousands of journeys disrupted, people's work and family lives badly impacted and the cost to the regional economy is in excess of £300m".
"Conductors in the RMT union transferred to the new customer service role (On-Board Supervisor) from the beginning of last month and are now operating effectively in that role. Her Majesty's Chief Inspector of Rail – the highest industry authority in the land – also says that drivers in sole control of the train is a safe method of operation.
"So the conclusion that most reasonable people will reach is that the RMT is seeking to hang on to its power to cancel trains. We've fully implemented our modernisation programme with the driver opening and closing the doors and a second person focused on customer service on our trains. Everyone is sick and tired of the RMT's strikes and their pointless and intransigent stance needs to stop, and stop now."