Unite general secretary Sharon Graham has backed Havering refuse workers planning five days of industrial action over working conditions.
More than 40 loaders and drivers employed by FCC Waste Management are scheduled to strike from 26 to 30 October.
The union says members have raised unresolved concerns about workloads, fatigue, hot-weather working, vehicle safety and welfare. It also highlights pay differences with comparable roles in neighbouring Redbridge.
Graham said the workers provided an essential community service and deserved their concerns to be addressed.
Havering Council has urged FCC and Unite to work constructively towards a negotiated resolution, saying it wants to minimise disruption to residents and essential services.
The council says it will remain in close contact with FCC as discussions continue.
The action is planned, and an agreement could still prevent it.
