Train drivers at LNER have voted to withdraw all non-contractual overtime in a dispute over terms and conditions.
Aslef said its members at LNER, which operates services on the East Coast main line, will take the action from November 27.
The row is separate from the pay dispute Aslef has with a number of train operators.
Mick Whelan, Aslef’s general secretary, said: “This dispute is about terms and conditions, not pay. It’s about the way the company has treated its staff – our members – and tried to ride roughshod over our working agreements.
“Since the start, this summer, of industrial action over pay – and our members at LNER have not had an increase in salary since 2019 – the company has taken the decision to treat every day as an “emergency” regardless of whether there was industrial action or not.
“The company has shown a complete disregard for the agreements which shape our members’ working lives.
“This has ranged from being pestered for favours and asked to work additional hours, even when they have made it clear that they do not wish to work their days off, to having turns (shifts) callously cancelled at short notice.
“Drivers have been asked to work in what should be their block annual leave, or have turns extended, forcing them to work longer hours than agreed for normal rostering.
“Unfortunately, due to this breakdown in industrial relations, and the company refusing to respect the agreements we have in place, we had to ballot our members for action.
‘It’s clear that our members are fed up with being treated like this, as more than 91% (on an 80% turnout) voted in favour of this action.
“Drivers don’t want to work endless overtime to paper over the cracks in the company’s structures, and they won’t be blamed for issues – the company’s failure to recruit, train and retain enough drivers to deliver the services they promise passengers they will run – which lie firmly at the door of LNER.”