Nursing assistants, food service workers and support staff at eight Twin Cities hospitals are voting this week on whether to authorize a two- to five-day strike.

The vote was called by the Service Employees International Union Healthcare Minnesota, which represents some 3,500 employees who have been in contract talks with the hospitals since January.

The union set up voting tables Monday outside three of the affected hospitals: Fairview Southdale, North Memorial Medical Center and Children's Hospital in Minneapolis.

The voting, which will continue through Tuesday, also involves workers at Methodist Hospital, Fairview Riverside, Children's in St. Paul, Bethesda Hospital and St. John's Hospital.

Tee McClenty, the union's chief negotiator, said the members are upset by concession demands from the hospitals that could increase their individual health insurance costs by thousands of dollars. She also said the two sides are far apart on wages, after the union agreed to a one-year wage freeze in the last contract three years ago. "We feel this is a corporate attack on the lowest-paid workers," she said.

A joint statement from the hospitals said they were disappointed by the strike vote and still hope to reach a settlement. "The hospitals are asking for reasonable changes to the current contract to be good stewards of our limited resources and the need for flexibility to adapt to an ever-changing health care world," according to the statement.

The two sides are scheduled to resume talks on Wednesday. The union is required to give 10 days' notice before a strike is called.

MAURA LERNER