Avanti West Coast workers to strike on New Year's Eve
The RMT says train managers will also walk out on January 2, and Sundays between January and May
Workers on Avanti West Coast are to stage a series of strikes after rejecting a deal aimed at resolving a dispute over rest day working.
The Rail, Maritime and Transport union said its members working as train managers will strike on New Year's Eve, January 2 and Sundays between January 12 and May 25.
An RMT spokesperson said: "Our members have resoundingly rejected Avanti's latest offers in two referendums and sustained strike action is now the only way to focus management's minds on reaching a negotiated settlement with the union."
The RMT said up to 400 of its members are involved in the dispute.
They voted by 83% against a suggested deal.
Avanti said it was looking at how the strikes will impact services and will confirm its plans as soon as possible.
Strikes planned for December 22, 23 and 29 were suspended last week after a suggested agreement was put to a referendum of RMT members.
An Avanti West Coast spokesperson said: "This strike action will cause significant disruption to our customers making journeys on the West Coast Main Line over an extended period.
"We're disappointed our train managers who are RMT members have voted to decline the very reasonable, revised offer made to them to resolve the rest day working dispute and avoid inconveniencing our customers.
"We remain open to working with the RMT to resolve the dispute."