Hopes of a deal to avert severe Christmas rail disruption were dashed on Monday night when the RMT union announced additional strike dates and rebuffed a pay offer from Network Rail just before the industry’s deadline. The union said it would put the offer to members in an electronic referendum this week but recommend that they reject it. It affirmed that two 48-hour strikes that will stop much of the railway next week would go ahead either way. The RMT general secretary, Mick Lynch, said: “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.” Rail workers will now also go on strike from 6pm on Christmas Eve until 7am on 27 December, curtailing some of the last passenger trains before Christmas and potentially disrupting a wide programme of engineering works on the railway. Most trains do not run on 25 or 26 December. However, the RMT has called off industrial action short of a strike, which included an overtime ban that insiders said could have caused even more widespread disruption. Some had feared that parts of the rail network would have been left almost as stretched during its planned work-to-rule period as on the eight days its members are scheduled to strike. Timetables will be reduced by 80% from Tuesday next week, during the first 48-hour wave of the series of strikes. The RMT’s national executive committee met on Monday afternoon to consider an improved offer from Network Rail, which raised pay for 2022 – backdated to January – by 5%, with another 4% at the start of 2023. The smaller TSSA union said it was calling off strike action in December while it balloted its members at Network Rail on the improved offer. The RMT had on Sunday rejected the first formal written offer from England’s major train operating companies and said it was seeking an “urgent meeting” with the Rail Delivery Group (RDG) as the offer included proposals that it said the employers and government knew would not be acceptable to its members. The union did not shift position after a last-ditch meeting on Monday. The RDG said it had offered an outline deal of 4% for 2022 and another 4% for 2023, dependent on workplace reform, as well as a guarantee of no compulsory redundancies until April 2024. However, the stipulations included one of the most bitterly disputed points of contention in industrial battles over the last decade – driver-only operation. Train operating companies want to give control of doors to the driver, which would mean they could run more services without guards or onboard crew, a measure that the drivers’ union Aslef and the RMT have opposed on safety and jobs grounds. Aslef, whose executive is meeting this week and could also call further strikes from late December, has told members it continues to oppose driver-only operation where it has not already been introduced. The RDG said it was “a fair and affordable offer in challenging times”, with revenue from fares still at about 20% below pre-pandemic levels and the industry requiring higher levels of subsidy from government to continue running. Operators were also seeking to include Sundays on contracts, rather than relying on overtime and rest day working. Apart from the Christmas bank holiday weekend, strike days were already planned for 13-14 and 16-17 December, and then on 3-4 and 6-7 January, with widespread disruption expected on days after the strikes. During previous national strikes this year, about 20% of trains have run, generally only between the hours of 7am to 7pm. The industry estimates it loses about £30m on each day of a national strike. The chaos in rail is likely to be intensified by a timetable change on 11 December that is due to add more trains, in particular to Avanti West Coast lines, and tackle issues on TransPennine Express (TPE) and Northern trains. Northern leaders have said the timetable is likely to further intensify problems on TPE, which has not been able to find enough staff to run existing services. Uncertainty over strikes, overtime working and timetable changes have left industry backroom staff stretched to the limit. Tony Miles, of Modern Railways Magazine, said: “The planners are trying to do the things that normally come in six-monthly bursts for four different days in a week.”