RMT to ballot conductors over Scotrail driver-only services
The union is asking staff if they want to walk-off the job in the dispute about safety.
The RMT union is to ballot ScotRail conductors for industrial action in a dispute over driver-only train services.
RMT, which is opposed to the extension of driver-only and driver-controlled services during the lifetime of the current Abellio ScotRail franchise, said it had not received the assurances it had sought on the issue from the operator.
These included guarantees the safety role of conductors and their role in operating train doors would not be reduced or abolished.
The union will begin balloting guards over a two-week period beginning on Tuesday.
RMT general secretary Mick Cash said the dispute had been declared after numerous meetings with the operator.
He said any extension of driver-operated or controlled trains would be "a clear attack'' on the terms and conditions of members.
Mr Cash said: "RMT members should not have to face the risk of their role and responsibilities being reduced and undermined.
"There is also a very real threat to passengers of watering down and wiping out the safety-critical role of the guard on these ScotRail services. That is a lethal gamble with basic rail safety.
"Those in charge of the Scottish Government cannot be allowed to wash their hands of the lethal scandal of de-staffing on Scotland's railways that is being cooked up on their watch.
"As well as the industrial campaign, RMT will be stepping up the political and public pressure over the extension of DOO (driver only operation) at the same time.
"RMT is in no doubt that our members will stand together and demonstrate the strength of feeling across the ScotRail network during this dispute. The union remains available for further talks.''