Thousands of rail maintenance workers are to stage a weekend strike later this month in a row over jobs and conditions which will threaten disruption to train services.
The Rail Maritime and Transport union said more than 12,000 of its members at Network Rail will walk out from mid-day on June 14 to the evening of the following day.
The 30-hour stoppage follows months of "fruitless" talks aimed at achieving a single set of terms and conditions for maintenance staff, many of whom transferred to NR from private firms.
RMT general secretary Bob Crow said: "The company has been using the talks to try to drive down our members' conditions, but our reps were shocked when the true extent of the company's agenda was revealed to them last week.
"We already knew that the company's idea of harmonisation was a wholesale attack on conditions, but on top of total flexibility, multi-skilling, dangerous cuts in team sizes and an end to any idea of work-life balance, they are now talking about a jobs cull as well.
"Our members' hard work and the £400 million in efficiencies they have already made have allowed NR to report pre-tax profits of more than £3 billion over the last two years.
"It is on the back of our members' hard work that the top bosses can expect bonuses worth between 50% and 100% of their salaries, yet they are telling us they can't afford real harmonisation.
"Instead we're being told that the 21% in new savings they have been told to make must be paid for by our members with their conditions and even their jobs, and that is unacceptable.
"Network Rail should be ashamed that it tried to head off a strike vote by conning our members that they could stay as they were when the company never had the slightest intention of allowing that to happen."
The RMT said it was merely seeking to establish that workers doing the same job received the same pay and conditions.
