Hundreds of senior conductors on Central Trains will stop issuing tickets from next Monday after voting to take industrial action in a row over rosters, it was announced yesterday.
The Rail Maritime and Transport union said more than 550 of its members will take other forms of action including refusing to cover for duties for depots other than their own.
The conductors have already taken three days of strike action after complaining about the introduction of new rosters.
RMT general secretary Bob Crow said the workers were united on the issue, adding: "It is time for the company to acknowledge our members’ strength of feeling and sit around the table to negotiate a sensible solution."
Passengers who board trains at unstaffed stations like Alvechurch, Barnt Green in Worcestershire, Henley-in-Arden in Warwickshire and Shenstone in Staffordshire, will not be penalised. Instead they will be able to pay for their ticket when they reach their destination.
Steve Banaghan, managing director of Central Trains, said he was "disappointed" by the RMT's latest move over the planned introduction of an electronic rostering system.
He said: "Since they walked out at Christmas and New Year over this issue and the issue of holiday payments, Central Trains has put two deals to the RMT, which although agreed nationally by the union, have subsequently been rejected by local negotiators.
"This includes a deal agreed with the involvement of ACAS last month. We're considering the implications of the latest action by the union which includes a ban on overtime, ticket collection duties and the legal position.
"But these actions will inevitably cause disruption to passengers if they go ahead. We have been and always will be available to talk to the RMT in contrast to their local negotiators who have made no concessions throughout these discussions in a bid to reach agreement and avoid further disruption."