The Rail, Maritime and Transport union said it had declared a dispute on West Midlands Trains, which operates across the region including Shropshire, over claims it plans to “bulldoze through” driver-only operation.
Preparations for a ballot of guards for strike action and action short of a strike are now under way.
RMT general secretary Mick Cash said: “RMT will never compromise on the issues of passenger safety and accessibility – the company knows that and should pull back from the threat to bulldoze through driver-only operation and the attack on the safety-critical role of the guard.
“We are preparing to ballot and we remain available for talks but it is down to the company to come back to the table with safe and sensible proposals that recognise the anger that their cash-driven plans have sparked amongst our members who deliver the service day in and day out.”
A West Midlands Trains spokesman said: “We reached a framework agreement with RMT in May last year, which guaranteed a safety-critical conductor would be retained on every passenger train. Dialogue has been ongoing but it appears the RMT has now changed its position.”
The operator announced improvements to services earlier this year, including a direct link fro Walsall to London. Other changes included increased Birmingham to Shrewsbury trains and faster services on the Chase Line.