Rail signallers in Stirling announced plans today for another round of strikes this weekend in a long-running dispute over shift work.
The RMT union said that due to the "sheer intransigence of the management" it was broadening its campaign "in light of the flagrant violation of existing rostering agreements by Network Rail."
Members working at Stirling Middle, Stirling North and Dunblane are walking out between 11.59pm on Friday and 11.58pm hours on Saturday.
The dispute is now one of the longest-running in Britain. RMT said it had tried to reach agreement with bosses over rosters "for many months."
The union said: "Regretfully, despite considerable efforts by RMT's local reps, the management refuses to budge on the call for the 12-hour shifts which would see staff working three days a week rather than five, reducing commutes and travel costs."
RMT has been sounding out all signalling members across Scotland in a series of meetings on how the dispute affects them, specifically management's refusal to operate and negotiate within terms of current rostering agreements.
The union said it had "not ruled out the option of escalating the action as a result of the current breakdown and in light of the implications for the wider signalling membership."
General secretary Bob Crow said: "This dispute has been dragging on for many months and management should be in no doubt of RMT's determination.
"Our members have shown their anger through support for the earlier waves of strike action with pickets out in force sending a clear message to the employers that RMT is determined to win this fight.
"We are now continuing to ratchet up the campaign and RMT remains available for meaningful talks."
Network Rail said the union's demand had been a "wholly unilateral initiative and has not been triggered by any changes by Network Rail."
It added that it would continue to engage in talks with RMT and through Acas.