SAN FRANCISCO -- Unionized hospital workers at San Francisco's California Pacific Medical Center continued their open-ended strike for a second day Wednesday, a job action aimed at forcing the hospital to accept a proposal by a federal mediator.

The strike started at 6 a.m. Tuesday and included approximately 800 workers, SEIU United Healthcare Workers West President Sal Rosselli said.

According to Rosselli, the compromise was submitted to both parties weeks ago in an attempt to avert a strike. The medical center initially agreed to the compromise but then reneged, claims Rosselli.

"CPMC totally reversed their position," he said. "We can only surmise that Sutter came down on them like a ton of bricks."

While CPMC receives advice and other resources from the Sutter network, which includes 26 hospitals in Northern California, the hospital bargains independently with unions.

Christine McMurry, a spokeswoman for the medical center, disputed Rosselli's version of the negotiations.

"CPMC made good-faith agreements with the union, and the union turned it down," said McMurry. "They twisted the facts, saying that we had reached an agreement when we hadn't."

McMurry said the union wants to organize all Sutter facilities and obtain "neutrality" for workers at CPMC. Neutrality, she explained, would prevent the hospital's administration from presenting its point of view to workers on the advantages and disadvantages of joining a union.

"We feel we should be able to talk with our employees as well about whether unions are a good idea for them," she said.

While she was concerned with the strike, McMurry said that SEIU United Healthcare Workers West represents 798 employees at the medical centers out of a total staff of 5,539 and "the majority are not directly involved in patient care."

McMurry said that striking workers' jobs would be waiting for them when they returned to work.

"This isn't a fight with our employees," she said. "We really do value our employees."

Originally the strike was scheduled to include workers at Sutter Health hospitals throughout the Bay Area, but it will only affect three San Francisco campuses of California Pacific Medical Center (CPMC).