New York state officials warned prison guards who are still participating in an ongoing wildcat strike Sunday to get back on the job — or prepare to be out of one — in an apparent last-ditch effort to end the illegal work stoppage.

Corrections officers received notices Saturday warning that strikers would have their health insurance coverage cancelled for them and their families effective Monday. State officials said they had done what they legally could by issuing a tentative prison strike deal before resorting to terminations and civil contempt charges.