Union officials will meet today to decide when as many as 4,800 nurses should strike against five Allina Health hospitals in a dispute over health benefits and workplace safety and staffing.

The lingering question is whether an announcement of an open-ended strike will serve to push Allina and its nurses into productive talks, or simply serve as an extension of an increasingly bitter labor dispute. A union official said late Friday that the two sides have agreed to talk again on Tuesday.

“Strike votes happen with much greater frequency than actual strikes,” said John Budd, a labor relations expert at the University of Minnesota. “It’s easy to imagine that any time there is a strike authorization vote, it’s almost always going to pass. It doesn’t mean a strike is necessarily going to occur, but the rank and file doesn’t want to pull the authority out from under its negotiators.”

Hospital nurses from across the Twin Cities went on a one-day protest strike in 2010, then voted for an open-ended strike that was avoided when negotiations resulted in a last-minute deal.

But nurses believe a prolonged strike is more likely this time because they are as adamant about preserving existing health benefits as Allina leaders are about eliminating four union-protected health plans and moving nurses to its corporate plans.

“We didn’t come to the table to negotiate the removal of our health care,” said Bernadine Engeldorf, a veteran nurse at Allina’s United Hospital in St. Paul.

Compromise seemed tantalizingly close in July — after nurses went on a one-week strike in June that cost Allina more than $20 million. Allina bent on its demand that nurses give up all four plans and offered to keep two of the plans for existing nurses if they agreed to pay the lion’s share of future cost increases.

The union countered with agreements to higher copays and deductibles in order to keep those two plans, but balked at Allina’s conditions that they felt would ultimately doom the plans over time by making them unaffordable.

The two sides could come no closer after making those offers, so the union opted to present Allina’s contract proposal to nurses and recommend that they vote to reject it. Nurses at Abbott Northwestern Hospital and Phillips Eye Institute in Minneapolis, Mercy Hospital in Coon Rapids, Unity Hospital in Fridley and United voted on Thursday by more than 2 to 1 against the contract — a margin that was necessary to authorize strike planning.

Allina officials believe nurses are misunderstanding the value of its corporate health plans. Two of the plans trade low premiums for high deductibles, making them attractive for younger or healthier nurses, while a third plan provides the most value when nurses use Allina doctors for their care, but covers outside providers as well.

“Our dispute isn’t over the scope of coverage,” Allina spokesman David Kanihan said in an e-mail. “It is about how to pay for the nurse-only plans that are quickly pricing themselves out of the marketplace.”

However, it is unclear whether compromise on health insurance alone will now be enough. The union had been willing in earlier negotiations to set aside its demands for ratios that assure adequate nursing staff to care for patients, but nurses at voting locations Thursday said staffing remained a prime concern along with efforts to assure their safety as they treat confused and sometimes volatile patients.

“I’ve been struck, I’ve been pushed over, I’ve been spit on,” said United nurse Caprice Bingham.

Allina officials have said the safety of its nurses and patients is a priority, and that improvements will take place regardless of contract negotiations.

The last open-ended nursing strike involving Allina nurses was in 1984, when 6,000 nurses from many hospital systems walked out for 38 days in a dispute over seniority and hiring and firing rules. At the time, it was the largest nursing strike in U.S. history.

The union has declared the latest strike on the grounds of unfair labor practices, claiming among other things that Allina negotiators have withheld requested information for evaluating their contract proposals. That is an important designation in most strikes, because it provides federal protection against being permanently replaced, but Budd said it isn’t as relevant in a nursing strike.

“In other industries, when someone is crossing the picket line or choosing to be a replacement, you’re usually thinking, ‘Here’s a job and if I like it, I’ll stay with it,’ ” Budd said. “In health care, replacements are already such a part of the landscape that the risk that they become permanent is less.”