Thousands of Boston nurses voted Monday to approve what would be the largest nurses strike in Massachusetts history.

About 3,300 nurses at Brigham and Women's Hospital authorized the one-day strike, which is set to take place on Monday, June 27. It would be the first in Boston in more than 20 years.

The move follows nine months of contract negotiations in which the union and hospital have been unable to agree on wages, health benefits and time off, Boston.com reported.

Trish Powers, chair of the MNA bargaining unit, said the daylong strike would render the hospital "inoperable."

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"They are taking a stand for the Brigham Way, for nursing excellence and safe patient care," Powers said in a statement. "When a corporation makes billions of dollars in revenue and hundreds of millions in profits, there is no reason why it should reduce nurse staffing, impact the quality of care for our patients and reduce nurse benefits."

The hospital says it has proposed a contract that is "fair, competitive, market-based and in line with operational and budgetary constraints."

Ninety-five percent of the registered nurses who are represented by the Massachusetts Nurses Association voted for the strike, according to State House News Service.

Both sides say they have held 19 bargaining sessions to reach an agreement on a new contract, most recently on June 1. The nurses' last contract expired Sept. 30, according to the union.

"We sincerely hope that we can reach a fair and reasonable contract and avoid a strike," Dr. Ron Walls, executive vice president and CEO of Brigham and Women's Health Care, said in a statement. "Our focus, however, remains on providing safe, high-quality care to our patients, and we will be ready to do so should a strike occur."

The hospital this month activated its Strike Planning Incident Command Structure to develop "a detailed operational and tactical plan to manage a strike, including contracting experienced nurses through a highly-reputable agency," the hospital said in a statement.

If the nurses go on strike, the hospital said, it would hire 700 temporary professional nurses to replace them for the duration of the strike.

Most nurses at the hospital earn between $38 and $68 per hour, with some earning more, according to an analysis in October by the Boston Globe.

Union leaders wrote in a statement that the hospital is making profits in the hundreds of mllions every year. They also said proposed salary increases in this round of budget negotiations are 1 percent across the board, and 0.5 percent for the nurses at the hospital who earn most. 

Brigham  nurses provide life-saving care every day and deserve a fair wage increase,” Powers said in the statement. “It is irresponsible that a hospital reaping enormous profits refuses to offer a fair wage increase to nurses while trying to create a two-tiered, union-busting benefit system.”

State House News Service contributed to this report.