NASHVILLE, Tenn. -- Tennessee is considering making it a felony to follow some versions of the Islamic code known as Shariah, the most severe measure yet put forth by a national movement whose members believe extremist Muslims want Shariah to supersede the Constitution.

The bill - drawn up by conservatives with ties to opponents of a planned Islamic center two blocks from New York City's ground zero and efforts to expand a mosque 30 miles southeast of Nashville - would face steep constitutional hurdles if enacted.

Nevertheless, it represents the boldest legislative attempt yet to limit how Muslims worship.

Muslim groups fear the measure would outlaw central tenets of Islam, such as praying five times a day toward Mecca, abstaining from alcohol or fasting for Ramadan.

"This is an anti-Muslim bill that makes it illegal to be a Muslim in the state of Tennessee," said Remziya Suleyman, policy coordinator for the Tennessee Immigrant and Refugee Rights Coalition, which was among several civil rights and interfaith groups that held a news conference Tuesday to oppose the proposal.

Nadeem Siddiqi, a 35-year-old American Muslim entrepreneur who drove about 160 miles from Knoxville to attend the event, said Shariah governs his life.

As written, he said the proposal is "overly broad" and "basically includes all Muslims and all their practices as being illegal."

"Shariah is how I know how to fast in the month of Ramadan; how I wash before my prayers," he said. "It also directs me in how much charity I need to give to the poor. It orders me to be honest and fair in my business dealings."

The bill's sponsor, Republican Sen. Bill Ketron of Murfreesboro, said the proposal exempts the peaceful practice of Islam but seeks to condemn those "who take Shariah law to the other extreme." He said it would give state and local law enforcement officials "a powerful counterterrorism tool."

Ketron, who has successfully pushed through bills tightening restrictions on illegal immigrants, said he expects the Shariah measure will become law. He said he doesn't have a problem with Muslims and is open to talking with them about their concerns.

"My daughter went to the prom with a Muslim," Ketron said. "I want to hear from them."

For now, supporters of the measure are working to bolster it against any constitutional challenges, which may be an impossible task, said First Amendment Center scholar Charles Haynes, who called it a "really distorted understanding of Shariah law."