A court decision in Israel to allow stores and restaurants to sell food banned by Jewish ritual law during the Passover holiday has angered the country's influential Orthodox Jewish community.

"The sale of leavened bread (during Passover) is a tough blow to the symbols of the Jewish nation," said Eli Yishai, a cabinet minister whose Orthodox Shas party is a key member of Prime Minister Ehud Olmert's coalition government.

To commemorate the biblical Israelites' hasty exodus from slavery in Egypt, ritual Jewish law forbids eating leavened products.

Keeping with that tradition, parliament passed a law in 1986 banning the display of unleavened food. Supermarkets put plastic covers on shelves of products that are not kosher for Passover and many restaurants close down for the week-long holiday.

But in a decision some religious Jews saw as an attack on their way of life, a Jerusalem court ruled two weeks ago that grocery stores and restaurants can display unleavened food because they are not "public areas" covered by the 1986 ban.

Israel's attorney-general said he supported the decision, further angering Orthodox communities, whose leaders threatened to launch protests and boycott establishments that sell food forbidden during the holiday, which begins on Saturday.

About 20 percent of Israel's population is Orthodox.

Looking for a way around the ruling, some Orthodox legislators proposed enacting new laws to ensure Passover traditions are followed.

"We have to protect and do our utmost to fortify the walls of Judaism in the land of Israel through legislation that will guard the unique Jewish character of the state of Israel," Yishai said.

Rabbis who lead Jerusalem's black-garbed ultra-Orthodox communities sent letters to 60 local businesses, warning their owners that "punishment for blasphemy, especially in the holy city, is very serious".

Jerusalem Mayor Uri Lupolianski, an Orthodox Jew, appealed to restaurant owners not to sell leavened products.

"I ask that this year we will continue, together, the tradition in Jerusalem of respecting the public's feelings," Lupolianski said on Army Radio.

Restaurant owner Ayal Lahav, who plans to sell bread and other unleavened products during Passover, said he was just trying to earn a living.

"To tell us not to eat or do something on Passover, the festival of freedom, is hypocrisy," Lahav told Army Radio.