Unite said the settlement revealed “ongoing mismanagement and incompetence” at the heart of the council.
Sharon Graham added the bin strike was “a direct result of the council’s mismanagement of its finances”.
Cotton, however, said he felt the authority had done “everything we reasonably could to resolve the dispute”.
“The big picture is that we cannot allow a position where there is equal pay injustice for workers in this authority or costs that have been placed on the taxpayers in this city,” he said.
“We’ve had a statutory consultation with the workforce and we’re still working through some of the final iterations of that, and with the workforce to identify alternatives… but clearly we’ve had to take these steps in order to take forward the changes we need to make to the service.”