Rail passengers in the West Midlands could be hit by industrial action at Christmas over an overtime dispute among conductors.

Hundreds of conductors are refusing to work on Christmas Eve, New Year’s Eve and New Year’s Day, threatening travel chaos for shoppers, workers and other customers.

Central Trains needs 150 conductors to volunteer to work on each of the three days in order to operate a service, but at present none of them have volunteered.

The train company is offering double time or a #220 lump sum to drivers, station workers and conductors.

After negotiations with the Rail Maritime and Transport Worker Union, station staff accepted the deal. ASLEF train drivers also volunteered to work.

A Central Trains spokesman said: "Conductors are in the same union as station staff but for some reason they haven't accepted the deal.

"We don't quite understand it because any conductors working that day would receive a guaranteed #220. We have about 550 conductors and we need 150 to run a service."

Last year a deal was struck four days before the Christmas holidays.

The spokesman continued: "Some people are probably working, or for another reason can't get away on the Saturday. They are the people who may be affected if trains do not run as planned.

"But it wouldn't be Christmas if there wasn't a dispute over extra pay."

An RMT official said the pay offer was not enough to tempt conductors away from their families on a Sunday – which is not currently part of their working week.

The union's regional organiser Ken Usher also stressed that the #220 on offer was in total, rather than in addition to a lieu day.

"The payment arrangements for staff expected to come in and work on Sunday, December 24, and on Sunday, December 31, are not good enough," he said.

"People are saying, 'I want to spend my time with my family' and the money is not enough to tempt them away. Further talks between Central Trains and the RMT are taking place at 10am today.

Meanwhile, hundreds of conductors and other workers at Midland Mainline - which operates from Yorkshire and the East Midlands to London St Pancras – will also walk out on Christmas Eve, New Year’s Eve and New Year’s Day. The RMT accused Midland Mainline of offering some workers half of a #200 lump sum given to drivers for working on the two Sundays over the festive season.

General secretary Bob Crow said: "All staff deserve equal recognition for their hard work over the year, so why the company has set about creating a two-tier workforce is beyond me – and it has angered our members.

"Everyone could do with an extra couple of hundred quid over Christmas, and no one likes being treated like a second-class citizen. Midland Mainline need to put this right."

The company said it would do its best to run a near normal service on strike days, adding that the enhanced pay was based on workers’ hourly rates.

Managing director Garry Raven said the extra pay was "generous" and that he was disappointed in the industrial action.