Rail union members are to lobby the Scottish Parliament as a dispute over driver-operated trains continues.
The RMT will stage a protest outside Holyrood on Thursday to call on the Scottish Government to pressure ScotRail to reach a settlement.
Talks between the union and ScotRail are ongoing through mediator Acas in an attempt to resolve the dispute before three further planned walkouts by staff.
RMT argues any extension of driver-only operation on trains would undermine passenger safety and staff terms and conditions.
In response, ScotRail says there are no plans for driver-only trains, with a second person scheduled to be on services after the introduction of new trains across the network next year.
RMT general secretary Mick Cash said: “Our members on ScotRail are standing firm and united in the industrial action as they fight to defend the safety-critical role of the guard.
“They are a credit to the trade union movement and we are proud of them.
“With a catalogue of serious safety breaches now emerging due to ScotRail’s cavalier attempt to run services with a crew of ill-trained and ill-prepared scab managers, it is now time for the Scottish Government to get off the fence and get involved.
“They need to wake up and start taking responsibility for what is happening on their watch.”