LNER train drivers are to go on strike every weekend between late August and early November, affecting passenger services between London and Edinburgh.
This comes after a breakdown in industrial relations, according to union Aslef, which accused the company of breaking agreements and bullying.
“The continued failure of the company to resolve long-standing industrial relations issues has forced us into this position," Aslef general secretary Mick Whelan said.
“The company has brutally, and repeatedly, broken diagramming and roster agreements, failed to adhere to the agreed bargaining machinery, and totally acted in bad faith.”
Drivers from the company will walk out on Saturdays between August 31 and November 9, alongside Sundays from September 1 to November 10.
This comes after a separate dispute over pay looked to be nearing an end this week following over two years of strikes as drivers were offered a 14% raise over three years.
“When we make an agreement, we stick to it. This company doesn’t,” Whelan added.