A protest has been held in London to mark three years since the start of the RMT’s dispute with Southern rail over the role of guards on trains.
Union members protested outside Keolis, which owns part of Southern’s parent firm Govia Thameslink (GTR).
The RMT has opposed the introduction of driver-only-operated trains (DOO) where drivers close doors instead of guards.
But Southern said since it made the change, services had improved. It urged the RMT to end its dispute.
RMT general secretary Mick Cash said the union had reached agreements with other train operators about the role of guards, but added: “Only on Southern have we been faced with such a stubborn and point-blank refusal to enter serious discussions.”
A Southern spokesman said: “Industry safety bodies have confirmed that having the doors closed by the driver is at least as as safe as by a conductor.
“We urge the RMT to end their unnecessary dispute.”
The RMT has said new figures obtained from Parliamentary answers showed at least 15,000 Southern services have run without a second person on board since DOO was introduced in 2017.
It claimed discrimination was taking place against older and disabled passengers who no longer had the guarantee of a second member of staff to help them.
Southern said a “tiny” fraction of services – most recently as little as 0.5% – had run without a second person on board and under the old arrangements would have been cancelled.
It said: “To help those in need of assistance we now have more staff on board our trains and complaints have fallen by a third.”