STAFF at rail union RMT walked out over an internal dispute today after being threatened at the union’s annual conference in Leeds, forcing it to close early.

The staff told the Star that supporters of an extremist faction operating within the RMT had called them “scabs” and “scum” and had threatened them.

The incident followed a vote at the meeting to overturn a decision by the union’s national leadership involving an internal appeal.

A letter from staff said: “Our integrity as staff has now been called into question by our own employer.

“As lifelong trade unionists who proudly work for the RMT, this is utterly unacceptable – an injury to one is an injury to all.

“We have consulted our GMB reps and, with their support, have determined we can no longer continue to work at this AGM and will consider our position further in respect of the AGM going forward.”

The union’s general secretary, Mick Lynch, wrote to his members: “I have been advised that our head office staff have entered into dispute with the union and have collectively decided to take industrial action today.

“That will mean that I am without administrative support or services until further notice.

“I will be seeking discussions with the GMB representatives and their trade union officials as soon as possible in order to address the issues and the situation.

“I hope you will understand that there won’t be an ability for head office to respond or provide services at this time.”

A union source said the staff are “loyal, hard-working trade unionists who have together given hundreds of years of service to the union.”