Talks to avert a strike by London Underground workers on the weekend of the FA Cup Final have broken down.
The talks at the conciliation service Acas ended without agreement because London Underground refused to give a guarantee of no victimisation of union members, the Rail Maritime and Transport Union said.
The three-day walkout, due to start on May 17, involves about 1,000 RMT members working on maintenance and engineering.
The union has accused LU of cutting train preparations, inspections and maintenance, which it says threatens safety.
General secretary Mick Cash said: "We are angry and frustrated that instead of talking seriously about the train inspection cuts, the company have resorted to threats of intimidation and harassment of our members and reps.
"LU bosses have wrecked the talks, and the action and protests scheduled for next week go ahead as planned."
Peter McNaught, director of asset operations for London Underground, said: "The safety of customers and staff is our top priority and our proposals do not compromise this.
"Train checks will continue daily, with every train thoroughly checked to guarantee safety.
"Our proposals are to change the frequencies of some less-safety-critical checks, with the regulator, the Office of Rail and Road, satisfied with our approach."
