The City Council is considering dipping into the city’s $2 billion health-benefits fund for retirees to find the cash needed to prevent 4,100 teacher layoffs, sources told The Post.

Council Speaker Christine Quinn (D-Manhattan) is hoping city unions come through on a potential deal to spend money from their own health-insurance fund to stave off layoffs. But with some unions balking at the idea, she is open to a last-ditch effort to tap retiree funds.

The council could legally use most of the retiree fund, but Bloomberg is likely to fight Quinn if she tries.