THE head office of rail union RMT remained closed today amid action by staff in an internal dispute.

Union staff walked out on Friday, forcing its annual conference in Leeds to be abandoned and the London HQ to close.

The walkout took place after some delegates were reported to have shouted “scabs” and “scum” at union staff.

Staff said they walked out after threats put them in fear for their safety.

Activists in the union belonging to some far-left organisations have long attacked the union’s elected national leadership.

A member of RMT staff said: “The shocking events at this year’s AGM should not be seen in isolation.

“In recent years a toxic culture of bullying, violence and harassment has been allowed to fester and grow inside the union, with the perpetrators receiving little or no punishment.

“RMT staff members feel threatened and vulnerable in their own workplace.

“Abuse and t‎hreats to staff via social media have become a matter of routine.

“Staff who have complained have seen those complaints kicked into the long grass for months on end, giving the perpetrators the green light to carry on with impunity.

“There is a stunning level of outright hypocrisy running throughout the organisation and its senior lay structures.

“If we don’t collectively get our own house in order those same employers will rightly call out RMT’s bare-faced hypocrisy to the detriment of the union’s members. The credibility of the union is now on the line.”

The union’s general secretary Mick Cash took early retirement this year, blaming a “campaign of harassment” against him from factions inside the union.

He was replaced by senior assistant general secretary Mick Lynch in May.