Unionized nurses at Eastern Maine Medical Center notified hospital officials over the weekend that they will go on strike Oct. 17 unless contract negotiations produce a breakthrough.

Late Friday night, leadership of the Maine State Nurses Association announced that more than 80 percent of voting nurses had voted to reject EMMC’s latest contract offer. On Saturday morning, the union gave the required 10-day notice of a pending one-day strike.

The walkout would begin at 7 a.m. Oct. 17 and would end 24 hours later. Hospital officials said they are preparing for the walkout and will bring in replacement nurses during the strike.

“We were expecting the strike notice as soon as they confirmed it with their members,” said EMMC spokeswoman Jill McDonald.

Negotiators with the nurses union began meeting with hospital officials in July. But despite progress on some issues, the two sides hung up over a union demand for a “professional practice committee” made up entirely of direct-care nurses.

The 870-member union sees the committee, modeled after a system in place in California hospitals, as key to fostering open and honest communication among direct-care nurses about issues important to patient care. The committee would make recommendations to improve care or to address nursing issues but would not have the authority to set change or set policy.

But EMMC officials describe the exclusion of managers from the committee as contrary to hospital policies on collaboration and transparency.

A representative for the Maine State Nurses Association, Judy Brown, said Sunday that the nurses are not trying to dictate anything to the hospital.

“We just want to have a committee that is an open forum for nurses,” said Brown, president of the union.

Brown said the union is ready to resume negotiations but the hospital has not requested another meeting.

McDonald deferred to an EMMC statement released late Friday after the union announced its membership had overwhelmingly rejected the hospital’s latest offer. In that statement, EMMC vice president and chief nursing officer Lorraine Rodgerson said the hospital will take the situation day by day.

“When this is all over, we will all still be here, working side by side,” Rodgerson said. “Our culture of mutual respect and commitment will see us through.”

This is the second strike notice presented to the hospital in recent weeks. The union called off the first notice after the two sides entered an emergency bargaining session with a federal mediator.

The two sides are expected to meet again with the Federal Labor Relations Board on Oct. 23.