The union said that its craft membership, which includes joiners, labourers, painters and electricians, voted to reject the COSLA pay offer by 69%, with 90% of those voting for industrial action.

Unite had recommended its local government craft membership reject the offer last month.

The revised pay offer was based on a proposal put forward by COSLA of a 3% increase for 99.7% of the local government workforce.

The local authority body said it has set aside £350 million for the increase.

An earlier proposal, rejected by GMB union members in June 2018, offered a 3% increase only to workers earning below £36,500, and a flat-rate increase of £1,600 for staff on higher grades.

A further pay offer, made on September 6, outlined a 3% raise for employees earning below £80,000. However, the trade unions also stated that they would advise members to reject this offer.

The craft membership will now jointly meet with Unite’s local government membership, who also voted to reject, to coordinate the next steps in the escalating dispute.

John Gillespie, the chair of Unite Scotland’s construction committee, said: “The emphatic result by our craft membership to reject the pay offer and also give clear support for industrial action must surely result in COSLA swiftly coming back to the negotiating table with a new offer. If they don’t, then Unite’s craft and local government membership will be moving forward to coordinate joint action.

“Ultimately, if this is not resolved by COSLA then it will mean widespread disruption across Scotland.”

Steven Dillon, Unite regional co-ordinating officer, added: “I fully support the mandate from our craft membership as our workers and their families have suffered pay freezes and real terms cuts for far too long. Workers are not taking the decision lightly to move towards industrial action but the derisory offer by COSLA have left them with no choice but defend themselves and their families.”