STAFF working for rail union RMT returned to work today after a four-day walk-out over an internal dispute.

The walk-out began at the union’s annual conference in Leeds on Friday, causing the meeting to be abandoned and RMT’s London headquarters to close.

Staff had allegedly been threatened and called “scabs” and “scum” by supporters of ultra-left factions within the union.

Talks on Monday led to an announcement that staff will be returning to work, although they remain in dispute with the RMT.

RMT general secretary Mick Lynch said in a message to staff: “I would ask that everyone involved takes matters forward together through discussions between the parties and that we work together amicably towards a mutual solution.

“I reiterate that everyone in our organisation has the entitlement to work in a safe environment and that mutual respect for each other is observed at all times.

“I look forward to working with you all.”