The union representing more than 4,000 nurses at the University of Michigan could be going on strike, officials said Monday.

The University of Michigan Professional Nurses Council said it has authorized a work stoppage of up to three days "to protest ongoing and continuous violations of their workplace rights."

Officials for Michigan Medicine, which oversees UM's hospitals and clinics, its medical school and medical group practice, called the union's move disappointing.

"We are disappointed that our UMPNC nurses have voted to approve a strike," Mary Masson, a Michigan Medicine spokeswoman. "We have been bargaining in good faith since January and have offered a competitive package."

She also said a strike could put patient safety at risk.

A date for the stoppage has not yet been set, the union said. Its members voted to authorize the strike during meetings held between Sept. 10 and Sunday. The council represents more than 5,700 registered nurses at University of Michigan hospitals, clinics and health care facilities.

“Our goal is not a work stoppage,” Katie Oppenheim, a nurse and the council's chairwoman, said in a statement. “Our goal is a fair agreement which respects nurses and guarantees safe staffing. The University can remedy this situation immediately, by stopping their unfair labor practices and bargaining in good faith."

Masson disputes the council's claims about staffing. She said Michigan Medicine was ranked No. 5 in the nation by U.S. News & World Report in August and its high ranking was achieved in part by the health system's excellent nurse-to-patient ratios, which she said are in the top 2 percent of all hospitals in the country.

Union officials said the labor organization has filed unfair labor practice charges with the state's Employment Relations Commission and alleges the university has failed to bargain terms and conditions of employment in good faith, has made changes in work shifts without negotiating with the union and discriminated against union members.

Masson said Michigan Medicine still hopes to avoid a work stoppage and remains ready to continue contract negotiations.

She said the university has offered nurses a deal that included across-the-board raises of at least 3 percent and six weeks of paid leave for physiological recovery from childbirth and six weeks of paid leave after birth, adoption or foster care.

Masson also said the union must give management official notice of a strike 10 days before members walk off the job.

In the meantime, she said Michigan Medicine has been developing a plan to continue operating in the event of a strike.

Part of the plan includes hiring and training temporary nurses to replace absent employees, adjusting schedules and deferring and rescheduling certain procedures, according to Masson.

"Michigan Medicine remains committed to patient safety during any union activity, and will do everything possible to maintain the highest quality of care during a strike," she said.

cramirez@detroitnews.com

Twitter: @CharlesERamirez