ScotRail drivers have rejected an improved pay offer from the newly-nationalised operator as chaos for passengers continues.
The national executive committee of the Aslef union announced it had knocked back a 4.2% wage increase tabled by the firm.
Almost 700 services have been scrapped in a “temporary timetable” drawn up during an impasse over an initial 2.2% pay rise offer branded “derisory” by the union.
The two parties returned to the negotiating table last week in the first progress to bridge the dispute and avert a strike.
But the union says it is determined to secure a “fair deal for members” and rejected the offer on Wednesday.
It now says they will move towards a ballot for industrial action if no agreement can be reached.
Aslef Scottish organiser Kevin Lindsay said: “Aslef wants to negotiate a fair deal for our members, we are once again calling on ScotRail to return to the talks, so we can negotiate a fair pay offer that we can put to our members.”
Drivers are currently refusing to work overtime or on rest days – leading to a third of daily services being cut.
Transport minister Jenny Gilruth came under fire on Tuesday after it emerged there was “no contingency plan” for measures if the pay deal was rejected.
She said ScotRail had made a “good offer” despite inflation being expected to reach 10%, and that getting a resolution was “absolutely essential”.
The national operator is also due to meet with the RMT to discuss pay, in connection with a separate dispute with Network Rail.
A Transport Scotland spokesperson said: “We are disappointed that Aslef, having given due consideration to the terms they negotiated, have decided to reject the very good offer on the table, an offer which is in part self-funded through increased revenue and efficiencies.
“We all need to work together to make nationalisation a success. Ministers are committed to ensuring that the railway unions are part of that success. However, to be part of the vision moving forward, the unions’ need to agree on a deal that is both fair and affordable, particularly in the context of wider public sector pay policy.
“While, regrettably, this decision appears to mean further disruption for passengers in the immediate term given there is no indication that drivers will return to previous rest day working and overtime arrangements, we would encourage all parties concerned to get back round the table to resume negotiations.”
David Simpson, ScotRail service delivery director, said: “We’re incredibly disappointed and frustrated that Aslef bosses have rejected this improved pay offer. It’s astonishing that they will not even put this offer to their members.
“Our substantially improved pay offer reflects the cost-of-living challenges faced by families across the country, while balancing it against the need to provide value for the taxpayer.
“We have offered to meet Aslef but, in the meantime, would urge them to reconsider this offer in the interest of their members and the future of the railway in Scotland.”