Up to 2,000 jobs could be cut by Bolton Council over the next four years, town hall bosses have confirmed.
The posts would go as a result of spending cuts, as the authority now estimates it could face having to make more than £70m of savings.
Chief executive Sean Harris said the council was trying to reduce the impact of the savings.
But Andrea Egan of the Unison union said members were extremely worried about the effects of the cuts.
The job cuts would take place over four years but Mr Harris said the council was trying to protect "services to the most vulnerable".
He added: "We are trying to generate jobs through the local economy and we are trying to mitigate of the job losses not just internally but also because a lot of our employees live in the borough."
Ms Egan said: "Our people are very concerned about their futures and their jobs."