More than 90 percent of Albertsons, Ralphs and Vons workers across Southern California who voted have turned down the chains' latest contract proposals, making a strike possible, union officials said.

While union leaders say the stores are trying to take away workers' health care benefits, the stores deny this claim.

In 2003 and 2004, a 141-day strike led some customers to make a long-term switch to independent grocers and specialty outlets.

"We don't want another strike, but we need to protect our health benefits for ourselves and our families," said Mario Frias, a Ralphs employee.

A federal mediator has asked for the vote totals and expects more negotiating sessions in the future, said Mickey Kasparian, president of United Food and Commercial Workers Local 135.

But if there isn't any positive movement after about five or six days, a strike could be called, Kasparian said.

"If we don't get a deal, we'll take this fight to the streets," the union leader said.

The grocery chains' officials have said that their proposal would limit employees' costs and raise company contributions to a health care fund. The proposal also would maintain the current prescription drug co-payments, the annual deductible and out-of-pocket maximums in the PPO plan.

The companies also have proposed to continue offering an HMO option, with no change to medication co-payments.

Kasparian said the proposal is inadequate.

"Like most supermarket workers, I work part time and make around $24,000 a year," said Victoria Frantz, an Albertsons employee. "I can't afford to pay thousands more so I can bring my kids to a doctor."

The grocery workers' union has more than 60,000 members in Southern California. Union members turned down a previous contract offer in April, and at the same time gave union leaders the authority to call a strike should they deem one necessary.

City News Service contributed to this report.