After ten years of working for a company in social services, can the management start requiring staff to work overnight shifts if the same type of schedule has been operating for the duration of the ten years?

No, they cannot, especially if there is a legitimate reason as to why you cannot work overnight. It is extremely important in the circumstances that you obtain legal advice. Please give us a call at the number below to discuss the situation in more detail. We would be happy to assist in any way we can.