The conciliation service Acas, which helps resolve strikes, is on the verge of an industrial dispute involving its own staff.
The Public and Commercial Services union, which represents 770 Acas employees, said it was involved in a row over plans to cut jobs and close offices.
National officer Steve Farley said: "Acas plays an important role as the champion of workplace consultation, yet Acas management are failing to practice what they preach.
"Huge decisions have been made about job losses and cuts to services but Acas management have refused to consult with the front line staff who provide those services about the changes.
"As a result, they've made some very bad decisions leading to a crisis within the service."
The union has submitted a petition to management, signed by over 400 workers, warning that morale has "plummeted."
An Acas spokeswoman said the organisation was reviewing its current structure and acknowledged that some of its smaller offices faced closure.
"We need to reduce the number of posts in the organisation, but the details of which posts and when are being discussed with the trade unions and staff.
"We are looking to cover this with voluntary severance and early retirement. Obviously, we take consultation seriously and we are always willing to talk to the unions."