The RDG said the offer was worth up to 8% over two years, but the RMT argued it would not offer job security and would likely result in thousands of job losses.

RMT members at Network Rail and across 14 train operating companies are due to start the first of four 48-hour strikes on 13 December.

The dates are 13-14 December, 16-17 December, 3-4 January and 6-7 January.

The RDG’s offer on Sunday included a 4% pay rise for this year, backdated to the start of the financial year, and a further 4% next year. It also promised a guarantee of no compulsory redundancies until April 2024.

In return, it is seeking changes to the way the UK’s trains are operated, including introducing more multi-skilled roles, more flexible working to increase staffing on Sundays, closing more ticket offices and rolling out more driver-only train operation.

The 14 train operating companies involved in the dispute are: Chiltern Railways, Cross Country Trains, Greater Anglia, LNER, East Midlands Railway, c2c, Great Western Railway, Northern Trains, South Eastern, South Western Railway, Transpennine Express, Avanti West Coast, West Midlands Trains and Govia-Thameslink Railway, which operates Gatwick Express and Thameslink services to Luton airport.

"We have rejected this offer as it does not meet any of our criteria for securing a settlement on long term job security, a decent pay rise and protecting working conditions," said RMT general secretary Mick Lynch, who is now seeking an urgent meeting with the RDG and Department for Transport on Monday (5 December).

"If this plan was implemented, it would not only mean the loss of thousands of jobs but the use of unsafe practices such as DOO [driver-only operation] and would leave our railways chronically understaffed," he continued.