Avanti West Coast train managers have voted to strike for three days over the Christmas period.
The RMT union said that walkouts have been scheduled for 22, 23 and 29 December for the London to Scotland service after rejecting the train company’s proposals for “rest day working arrangements”.
Train managers usually work a four-day week but due to staff shortages can be asked to work on rest days but the RMT said that the current arrangements are “unacceptable”.
Avanti West Coast has been contacted for comment.
The strikes have been announced just weeks after the RMT accepted a backdated pay rise of 5% from the Rail Delivery Group, the body which represents train companies.
But a dispute remained over planned changes to working practices and talks over future pay.
The RMT’s general secretary Mick Lynch said: “Train managers are being treated unfairly compared to senior managers, who receive significant payments for covering these roles.
“Our members have had enough, and this strike action demonstrates their determination to win a fair deal.”