SACRAMENTO (AP) - In 2004, the California Legislature gave foie gras producers seven years to find a humane way to create the duck liver delicacy without inhumanely forcing food down the birds' throats.

With the July 1 deadline looming, an attempt Monday by some of the state's top chefs to overturn the law has done more than just ruffle the feathers of the bill's original sponsor.

"I gave them seven years — seven years and I shouldn't have — and now they're all going, 'Oh my God, I just don't know how we're going to survive,'" former president pro tem of the state Senate, John Burton, said without trying to measure his anger. "I'm so infuriated with the bad faith going on here that words cannot describe it."

Burton's bill banned the "inhumane practice" of force-feeding ducks and geese as well as the sale of foie gras in California. Burton initially agreed to delay implementation of the bill because the state's sole producer had asked for time to find a more humane way to engorge the birds' livers to keep the dish on menus.

Now a group of 100 chefs have signed a petition saying they want to keep the sale of foie gras legal and establish new regulations for raising the birds.

"It's been a rough couple of years for restaurants because of the economy," said Nathan Ballard, spokesman for the group who delivered the petition to the office of Assembly Speaker John Perez on Monday. "This is one more blow to the restaurant industry in California. Chefs don't want to see it go into effect."

At least one renowned chef supports the ban. Wolfgang Puck wrote a letter in February to California chefs who still had foie gras on their menus and asked them to embrace the ban.

"We chefs have the ability to create delicious and original dishes our customers will love without causing torment to animals," wrote the celebrity chef who was among the first to use cage-free eggs and pork from sows not confined during pregnancy in tiny gestation crates.

Foie gras, French for "fat liver," is created by the funnel-forced ingestion of large amounts of feed into the duck's esophagus. Eventually the liver grows to more than 10 times its normal size.

The chefs who opposed the ban — most from the San Francisco Bay Area — also are using an animal welfare argument. Calling themselves the Coalition for Humane and Ethical Farming Standards, or CHEFS, they are asking the state to set standards for foie gras production that would include audits by animal welfare experts, cage-free birds, hand feeding by methods that don't impair breathing, and limits on fattening. They say that if foie gras is outlawed, people will buy it on the black market.

Ballard says as part of the original bill, a deal was engineered that would have required the state to study more humane ways of raising birds that are slaughtered for foie gras, which it has not done. Burton, who sponsored the original bill, said that claim is not true or it would have been written into the bill.

A message and email left by The Associated Press with Sonoma Foie Gras, the state's only producer, was not immediately answered. In addition to liver, the company also processes and sells duck meat. The company's website says the ducks live for two months freely roaming a walnut orchard until they are placed in a 33-square-foot pen with a dozen other birds for fattening.

"They've had seven years to find another way to produce this delicacy," said Jennifer Fearing, California director of the Humane Society of the United States. "They should have used it productively."

Burton, now the state Democratic Party chairman, had heard the attempt to undo his legislation was in the works, so on April 4 he sent a letter to many members of the Legislature reminding them of the history of negotiations and the reason he granted the delay.

"They're saying it's going to hurt their business, but we can remember they said if people couldn't smoke in restaurants and bars, they would go out of business then, too," Burton said Monday. "If they think this practice is not a problem then let them all sit at a table and let someone cram food down their throats."