The Rail, Maritime and Transport (RMT) union have announced more strikes after it rebuffed a new pay offer from Network Rail, dashing hopes that Christmas rail chaos could be averted.
The RMT said that members will be asked in a referendum this week whether they want to take the offer, although union bosses have recommended they reject it.
Its national executive committee met on Monday afternoon to consider an improved offer from Network Rail, a 5% pay rise this year and 4% next year.
The offer also guaranteed there would be no compulsory redundancies for workers who are not managers until 31 January 2025 and includes a 75% discount on leisure travel for staff and their family members.
The RMT described the offer as "not acceptable".
Members at Network Rail are being urged to reject the new proposals and proceed with walkouts on 13-14 and 16-17 December.
The union has also announced another 48-hour strike from 6pm on Christmas Eve to 6am 27 December.
Government minister Nick Gibb has urged the RMT union not to "hold the country to ransom" following the announcement.
Transport secretary Mark Harper described the escalation as "incredibly disappointing" despite a “new and improved deal offering job security and a fair pay rise”.
Mick Lynch, the RMT’s general secretary, told BBC Radio 4’s Today programme: “We feel that we’ve been compelled to take this action due to the intransigence of the government. We’ve been faced with an extremely detrimental offer and our members simply aren’t in a position to accept the changes the companies have put on the table."
He argued wages are being lowered against soaring inflation, which is just above 11%, while conditions are being “ripped up”.
The RMT, which also represents workers at 14 train operating companies, did however call off industrial action which included an overtime ban from 18 December until 2 January, which some experts feared would be even more damaging to the network.
There is two further 48-hour strikes in January on the 3-4 and the 6-7.
Hundreds of thousands of workers across many sections of the economy are planning to strike this month and in January, with walkouts every day until Christmas in what is being dubbed a "new winter of discontent".
Nurses, 999 call handlers, paramedics and other ambulance staff, teachers, postal workers, border force officers, bus drivers passport and National Highways employees are all set to walk out in disputes over pay, conditions and contracts.
Yesterday, Shelter staff announced an "unprecedented" strike, with 600 workers to walk out at one of the charity’s busiest times of year.