The Alliance Defense Fund of Scottsdale, Ariz., is recruiting ministers to make political sermons Sept. 28, a few weeks before the presidential election, The Wall Street Journal reported Friday. The group hopes to challenge the constitutionality of the tax law, the report said.

Erik Stanley, senior legal counsel for the alliance, said about 80 ministers, including a Catholic priest, have said they might join the protest. He said he hopes to get 40 to 50 to participate, including some liberals.

The Rev. Steve Riggle of Grace Community Church in Houston said he told his flock before the Texas primary he supported former Arkansas Gov. Mike Huckabee.

"The government should not be telling the church what it should or should not be saying," Riggle said. "As a pastor, a private citizen, I can speak for myself. The IRS cannot quench my voice."

Rob Boston of Americans United for Separation of Church and State said the tax exemption granted churches "comes with conditions."

"So if any pastor out there feels he is gagged or can't speak on partisan politics ... forgo the tax exemption and say what you want," said Boston.

Federal law prohibits churches from endorsing political candidates, but they are permitted to advocate positions on issues.