More than 200,000 homes across Manchester could be left without bin collections for a total of more than four weeks as workers are set to walk out in a dispute over pay.
GMB and Unite union members employed by Biffa, who make up more than half of the workforce, voted overwhelmingly in favour of industrial action.
The outsourced waste management company which has a contract with Manchester City Council for bin collections offered most of its staff a 1.75% pay rise worth 17p an hour.
The GMB Union says Biffa is trying to enforce a real terms pay cut and is warning householders face "chaos" in the coming months as its members protest the offer.
Both unions are due to begin the action on Tuesday 3 May 2022 and will continue to 13 May with a further two-week strike planned from 23 May until 4 June.
The GMB says that in spite of extensive negotiations, Biffa has refused to increase its offer.
The workers include drivers, loaders and environmental operatives.
Michael Clark, GMB Regional Organiser, said: “More than 200,000 homes now face bin chaos because Biffa is trying to force through a real terms pay cut.
"Refuse collectors worked through the pandemic – meaning Biffa continued to make a healthy profit.
“Now Biffa needs to give something back to those workers.
“GMB calls on Biffa to make a decent offer and head off this industrial action.”
A spokesperson for Manchester City Council said: "The negotiations are ongoing between Biffa and the unions and we would urge them to reach an agreed way forward to avoid disruption to Manchester residents.
"We are continuing to work with Biffa to explore contingency plans to mitigate the potential impact of industrial action to help minimise the impact on refuse collection in the city and to ensure our streets are kept clean.
"These plans will respond to the exact nature and extent of the industrial action, and we will look to limit the disruption to residents as much as possible."
A Biffa spokesperson said: "We are in active and ongoing negotiations with the unions and remain committed to reaching a solution as quickly as possible."