Residents of Southern California face a widening grocery store strike that threatens to disrupt the Thanksgiving holiday Thursday. Nine thousand delivery drivers have joined the work stoppage, which has spread to Northern California and may spread even further.

For more than six weeks, picketers at Southern California's largest supermarket chains, Vons, Ralphs, and Albertson stores, have urged shoppers to take their business elsewhere. The workers are striking against one chain, and the other two companies have locked out their workers and hired non-union replacements.

The dispute is largely over health care benefits. The companies say intense competition from retail giants like Wal-Mart has made those benefits too expensive and workers must share the cost. Workers say they cannot afford to.

This week, the Teamsters union joined the stoppage, as the clerks began picketing regional distribution centers for the supermarkets. The teamsters drive the trucks that deliver food to the stores, and the strikers hope to cut store sales before the holiday, putting pressure on the companies to reach a settlement. Thanksgiving is a time when many families eat elaborate dinners of turkey and other traditional dishes.

Striking clerks have set up picket lines at the affected markets in San Francisco and other parts of Northern California. Later, they say they may picket Safeway stores in Washington D.C. and neighboring Maryland. Safeway's parent company owns one of the affected California chains.

Contract talks are stalled. Teamsters' regional vice president Jim Santangelo says strikers hope consumers can help them press their case.

"They're our heroes right now because they've been supporting us," he said. "I just hope they continue to support us."

Some shoppers ignore the picket lines, but informal surveys show that business dropped dramatically in the early days of the strike as many shoppers took their business elsewhere. The work stoppage has helped small chains and family-owned markets.

The strike is now in its 45th day, and this shopper, at first reluctant to cross the picket lines, is getting frustrated.

"I mainly use the other stores, but it's been long enough, and now I'm crossing the picket line," she said.

Another shopper ignores the picketers.

"I feel sorry for them, but that's their personal fight," she said. "I have to keep shopping."

The affected supermarkets say they have made contingency plans and have plenty of turkeys on hand for the Thanksgiving holiday.