ScotRail engineers have ended a dispute with the operator – but services are still facing significant disruption during COP26 as other workers have rejected a further pay deal.
Unite says about 250 of its members – who provide maintenance and repair services for rolling stock – have accepted an offer from the firm.
It follows a months-long dispute which threatened to continue during the climate change conference in Glasgow.
But the threat of a series of 24-hour walkouts has now come to an end.
However, RMT has confirmed its members – which includes on-board train staff – have turned down the latest offer in their own long-running dispute with ScotRail.
It means that strike action is set to go ahead as thousands of people descend on Glasgow next week for the summit, with ScotRail warning of severe disruption to services.
First Minister Nicola Sturgeon has previously been urged to intervene in the row.
In a statement released on Monday, after a vote on the latest offer at the RMT AGM in Leeds, general secretary Mick Lynch said: “RMT is a democratic organisation and following a string of impassioned speeches by ScotRail, delegates our AGM has voted to reject this offer, to support our Scottish members and to press ahead with the action throughout COP26.
“We have been given a wholly arbitrary deadline of 5pm on Wednesday to accept this deal or the whole pay offer will be pulled.
‘Gun pointed at head’ during negotiations – union
“You cannot conduct serious negotiations with that sort of gun pointed at your head.
“Our message to Nicola Sturgeon, Transport Scotland, Abellio and Serco is that there is still time to resolve the pay disputes but it requires some serious movement, the lifting of bogus deadlines and genuine talks.
“The union is available to get those talks on any time, any place, anywhere.”
Ian McConnell, ScotRail’s chief operating officer, said: “I’m incredibly disappointed and astonished that RMT representatives have, once again, rejected our latest enhanced proposal without allowing nearly 2,000 members a vote.
“They have not only let down their members, but the travelling public too. Quite clearly, RMT leadership have had one objective through these negotiations and that is to disrupt Scotland’s Railway’s role during COP26.
I want to reassure customers and COP26 delegates that we are continuing with our contingency plans – ScotRail
“RMT members now stand to lose a pay rise worth 4.7 per cent over two years, a £300 payment for COP26, and a rest day working enhancement, as well as the loss of 12 days pay during strike action.
“While the pay offer remains on the table, I want to reassure customers and COP26 delegates that we are continuing with our contingency plans and we will communicate these in the coming days.
“We are working hard to provide a core service for COP26, however, people should expect significant disruption and extremely limited rail services during the industrial action.”
Speaking on Unite’s deal for engineers, industrial officer Pat McIlvogue said: “After a long and arduous journey with Abellio ScotRail we have finally reached an agreement with the company over our pay dispute.
“It shouldn’t have been this difficult to achieve and it shouldn’t have been taken to the wire by Abellio ScotRail.
“This deal will ensure our members receive a significant pay award over two years, while a number of the outstanding issues we have such as rest day working are being ironed out.
“We are satisfied that our members, who ultimately made this democratic decision, have got a deal which rewards their hard work, and strike action by Unite members has now been averted with COP26 just around the corner.”