There was disappointing news yesterday for rail users hopeful that ScotRail services could soon get back to normal.
It emerged that train drivers' union Aslef has rejected the latest 4.2% pay deal.
The union's national executive said it would ballot for industrial action unless ScotRail offered further talks.
Many drivers have been refusing to work overtime or on rest days during the pay dispute.
A driver shortage has led to the now-nationalised train operator cutting a third of services under a temporary timetable.
ScotRail said it was frustrated by the decision of Aslef and described the decision not to put the improved pay deal to its members as "astonishing".
Transport Scotland said it was disappointed the union had rejected a deal which it described as "both fair and affordable".
Scotland's Transport Minister Jenny Gilruth had said earlier this week she was hopeful the 4.2% pay offer would resolve the dispute.
However, it was turned down by a meeting of Aslef's national executive committee on Wednesday.
Scottish organiser Kevin Lindsay told the BBC: "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."
ScotRail's service delivery director, David Simpson, urged the union to reconsider the pay offer, which includes an improved maternity and adoption leave and a 10% increase in the Sunday working allowance.
He 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."
Scottish Conservatives' transport spokesman Graham Simpson accused the government of "complacency" over the situation.
"It's clear she (Jenny Gilruth) and the SNP government just assumed the offer would be accepted," he said.
"Now, it appears we're back to square one and the Scottish public will have to endure the woefully-inadequate reduced ScotRail timetable for even longer."
Economist Tony Mackay has estimated the pay row could cost the Scottish economy between £75million and £80million every week from a combination of the fall in economic output and extra money having to be spent by travellers to get to their destinations.