The drivers union Aslef is to ballot ScotRail members for an overtime ban as they seek to improve basic wages.
They have already voted to reject the company's last offer of a 6.4% pay rise, and are now considering industrial action short of a strike.
Kevin Lindsay, the Aslef organiser in Scotland, said the train company's drivers were the among the poorest paid in the industry.
They have called on ScotRail to come back with a better offer or face industrial action.
He added: "We are still looking for a negotiated settlement and there is still time for negotiations. But we are looking to ScotRail to come back with an improved offer as our members have rejected what was on the table.
"They are fed up with being at the bottom of the pay league, among the privatised train operating companies in Britain, and they want ScotRail to remedy that situation.'
A company spokesman said the current pay offer would have taken drivers pay above the £40,000 threshhold, and called for talks to resume.
He said: "We are extremely disappointed that the offer of 6.4% over the next 18 months has been rejected.
"That offer, which would take drivers' basic pay to almost £42,000, is a very good one in the current economic climate.
"It also coincides with our continued investment in the railways - and in increasing jobs at a time of rising unemployment in Scotland.
"Our doors remain open for discussions."