WORCESTER, Mass. - St. Vincent Hospital nurses have filed a charge of unfair labor practice against Tenet Healthcare.

According to the Massachusetts Nurses Association, Tenet is pursuing a plan to impose 12-hour shifts on nurses working on the inpatient units and the emergency department, which they said violates the agreement reached to end their strike and would affect 250 nurses.

St. Vincent Hospital is backing their decision to transition nurses to 12-hour shifts, saying it will enhance recruitment and retention of staff.

The hospital said its collective bargaining agreement with the MNA gives them the right to move nurses to 12-hour shifts with 30 days' notice. In a statement, the hospital said, "Although we are not obligated to negotiate with the MNA on this issue, we offered to meet and confer. We also provided them with far more notice than the collective bargaining agreement requires."

The MNA said nurses think the plan shows disregard for the impact this change will have on many of the nurses’ family life, personal wellbeing and ability to provide safe care under those conditions.

The MNA filed the charge with the National Labor Relations Board and filed a request for injunction to prevent the plan from happening on May 1.