The bin collector strike in Glasgow is back on during COP26 after a pay offer was rejected.
A statement from GMB Scotland said members plan to walk out at midnight on Sunday as world leaders begin to arrive in the city for the climate summit.
The union said the council failed to give members “the proper time and space to consider the 11th hour offer from Cosla”.
The planned strike action was previously called off on Friday after a new pay offer from council umbrella body Cosla. GMB Scotland then said it would suspend the strike for two weeks to consult with members.
GMB Scotland Secretary Louise Gilmour said: “The council has failed to give our members the proper time and space to consider the 11th hour offer from Cosla, and the fact the council moved to block strike action in the Court of Session using anti-trade union legislation, means there is too much bad faith among members towards the employer.
“Therefore, our members in cleansing have informed us that they will still proceed with the planned strike action from 00.01am Monday, November 1.
“We are calling for an urgent meeting with the council as soon as possible and we will work until one-minute to midnight tonight to try and fix this.
“We have also made the Scottish Government aware of the situation and are liaising with the First Minister’s Office, but without any further dialogue the cleansing service in Glasgow City Council will take strike action from tomorrow and throughout the first full week of the COP26 summit.”
The GMB was calling for a £2000 pay rise and previously turned down an offer of an £850 a year increase for staff earning up to £25,000.
The Cosla proposal tabled on Friday is for a one-year, 5.89% increase for the lowest paid council staff, as part of a £1062 rise for all staff earning below £25,000.
The Scottish Government gave £30m to support the offer.
Glasgow City Council and Cosla have been contacted for comment.