Cleansing workers and schools support staff who are members of the GMB union voted in favour of industrial action that could disrupt the climate summit starting next month.
A total of 1,500 Glasgow City Council staff in the refuse, cleansing, school janitorial and catering sectors could strike because of the ongoing pay dispute, with 96.9 per cent of returned ballots backing industrial action.
GMB members rejected a £850-a-year increase for staff earning up to £25,000 a year from local authority umbrella body Cosla, with the union – along with Unison and Unite – all calling for a £2,000 pay rise.
Cosla said negotiations are ongoing.
GMB Glasgow organiser, Chris Mitchell, said: “Over the past 18 months throughout this awful pandemic, essential services across Scotland have been held together by an army of low paid workers.
“We were called key workers, even Covid heroes, but while politicians were happy to applaud us on Thursday nights, they’ve never put their hands in their pockets to pay us properly.
“The eyes of the world will be on Glasgow during COP26, and our politicians now have a choice – will they fairly reward the frontline workers who got the country through the pandemic, or will they risk embarrassing the city and the country on an international stage?
“The message that our members have sent with this ballot result is clear. We are taking a stand for what we deserve, and we believe the people will stand with us.”
The call for industrial action comes after Glasgow City Council leader Susan Aitken was criticised for saying the city needs a “spruce up” before the COP26 conference.
Her comments received a backlash from politicians and members of the public who claimed she was “out of touch” with the city.
A Cosla spokesman said: “We appreciate everything that Local Government workers have been doing, and continue to do, to support people and communities during the pandemic and as we begin to recover.
“We continue with ongoing, constructive negotiations.”
Rail workers will also go on strike during COP26, the RMT union confirmed on Thursday, over a separate dispute over pay and conditions.
ScotRail staff will strike from Monday November 1 until Friday November 12.
Staff on the Caledonian Sleeper will hold two 24-hour strikes: one from 11.59am on Sunday October 31 and one on Thursday November 11, also from 11.59am.