The strike by Avanti West Coast train managers has resumed after an offer to resolve a dispute over working on rest days was rejected.
RMT union members will now demonstrate on New Year's Eve and January 2, as well as every Sunday from January 12 to May 25.
The union said a “sustained strike” was now “the only way to focus management's attention on reaching a negotiated settlement.”
Avanti West Coast, which operates trains between London and Scotland and across the West Midlands and north-west England, said the strikes would cause “significant disruption” to customers.
Last week, the RMT canceled strikes planned for December 22, 23 and 29 to consider Avanti's new offer.
But the union said Tuesday evening that 83 percent of the 400 members involved in the dispute had voted against the deal.
The revised offer included higher pay for rest days and a more organized distribution of shifts during rest days, he said.
Conductors typically work 41 hours per week, but due to staff shortages, they may be asked to work on their days off. The RMT said the current arrangements were “unacceptable”.
Avanti said in response to the latest announced strikes that it was “disappointed” by the vote against a “very reasonable” revised offer.
“This strike action will cause significant disruption to our customers traveling on the West Coast Main Line for an extended period,” a statement said.
“We remain open to working with the RMT to resolve the dispute.”
It said it was studying the impact of the strikes on services and would confirm its plans as soon as possible.
Since mid-2022, rail transport has been disrupted by industrial action as the RMT and train drivers' union Aslef demanded better pay and conditions for their members.
The previous Conservative government said in return that changes to working practices were needed, but Labor struck a deal with the unions after winning the general election.
