Talks aimed at resolving the Southern Railway dispute have ended without agreement, the company said.
Aslef members are set to go on strike again on Friday in the third day of industrial action this week.
The long-running saga is over union opposition to driver-only trains, with concerns passenger safety will be compromised if drivers are responsible for closing doors using in-cab monitors.
Drivers' union Aslef said that "progress had been made" in talks aimed at resolving the Southern Railway dispute but Friday's strike will still go ahead.
Talks between Southern and the union have been adjourned until tomorrow.
Southern Railway services will be at a standstill again on Friday after talks over driver-only trains collapsed.
Talks aimed at resolving the Southern Railway drivers' dispute will be held at the conciliation service Acas.
Commuters have been taking to social media to express their frustration at the latest Southern Rail strike.