Rank and file members of the union that represents roughly 1,500 nurses Children's Minnesota facilities in St. Paul and Minneapolis are voting Thursday on a contract offer from the health system. The workers could accept the deal, reject it, or both reject it and authorize a strike.

"We do not like the last offer from the hospital," said pediatric intensive care unit nurse Elaina Hane who works at Children's Minnesota, St. Paul and is on the union's negotiating committee.

Hane said the main sticking point for her group is the increasing cost of member's health insurance.

"We need a 67 percent vote to authorize a strike, but only a 51 percent vote to say no," Hane said.

Even with the possible strike authorization, more negotiations are scheduled for Friday. If union leaders get the go ahead to call a strike, they could do so at any time. But any walkout would first be subject to a ten-day waiting period.

Children's said it hadn't anticipated the vote. Management claims it's working in good faith toward a settlement.

"We are surprised that they're holding a strike vote at this juncture in the negotiations," said Katie Penson, the senior director of clinical services at Children's Minnesota.

Penson said the union has rejected management's request for mediation. "We have asked the union several times if we could enlist the help of a federal mediator to help reach resolution," said Penson.

The contract dispute at Children's is part of a much larger round of nurse's union negotiations with six Twin Cities area health systems. About 5,000 Alina Health nurses staged two strikes beginning in June of 2016 and ending in October of that year.