As the country grapples with its worst economic downturn in decades and persistent unemployment, voters in Oklahoma next week will take up another issue — whether they should pass a constitutional amendment outlawing Islamic law, or Sharia.

Supporters of the initiative acknowledge that they do not know of a single case of Sharia being used in Oklahoma, which has only 15,000 Muslims.

“Oklahoma does not have that problem yet,” said Republican state Rep. Rex Duncan, the author of the ballot measure, who says supporters in more than a dozen states are ready to place similar initiatives before voters in 2012. “But why wait until it’s in the courts?”

Some conservative activists contend that the United States is at risk of falling under Sharia law. They point to Europe, with its larger Muslim population and various accommodations to the Islamic religious law.

In England, Muslims can enter special Sharia courts to decide divorce and custody cases if both parties agree.

In the United States, those who warn of the dangers of Sharia can point to only a handful of cases that merely allude to the centuries-old, complex tangle of Muslim religious law. And in none of the cases cited has any U.S. court held that Sharia law is the law of the land here.

Islamic groups say the Oklahoma initiative, which was placed on the ballot by the Legislature, is nothing more than an effort to stigmatize their religion in order to whip up votes. “There’s no threat of Sharia law coming to Oklahoma and America, period,” said Saad Mohammed of the Islamic Society of Greater Oklahoma City. “It’s just a scare tactic.”

Until recently there was little campaigning over the measure, known as State Question 755. In July, the only public poll conducted on the matter found it had the support of 49 percent of voters, with 24 percent opposed and 27 percent undecided.

Last week a group called Act! for America, which says it exists to fight radical Islam, began airing radio ads and making automated calls to Oklahoma voters, urging approval of the amendment.

“The threat at this point is not that a country in Europe or the U.S. will formally adopt Sharia law, but that Sharia law will be accommodated alongside Western law,” said Guy Rodgers, the group’s executive director.