Mean, Nasty & Tired
We had a similar situation on afternoon shift. Manager came in for a 'chat' and started probing for answers to what would make L.A.M.E's happy.
Seems the cracks are beginning to show. To our credit (I believe) we didn't give them anything.
Rule One of negotiation: Let them show their hand before you show yours. They may be willing to offer much more than we ever thought possible to make their problems go away.
And one things for sure. If they DO offer something descent, their problems will 'go away' very quickly.