The House Republican tax plan would upend a longstanding measure, known as the Johnson Amendment, that prohibits politicking from the pulpit, and critics say it could turn churches into new conduits for political money.

Under current law, churches, charities and other 501(c)(3) tax-exempt organizations are prohibited from endorsing political candidates. The bill released Thursday would allow churches to make statements about political campaigns and candidates in the course of religious services and activities, according to section 5201 of the measure.

A pastor, for example, could endorse a candidate for office, or oppose one, during Sunday service.

That type of politicking would not compromise a church’s nonprofit status, so long as its expenses related to such matters were considered de minimus, the bill summary said.

The liberal group Public Citizen said it was fighting the proposal.

If enacted, the move could favor wealthy political donors “who want a new avenue to funnel their secret cash, and want to do so while receiving American tax dollars in the form of a deduction,” said Public Citizen’s Lisa Gilbert.

“These groups must be allowed to pursue their missions, and should not be subjected to unrelated and divisive partisan politicking,” she added. “The change proposed in the House bill would lay waste to a space in which Americans join together to gain spiritual guidance, work to improve lives, and solve issues we face as a country.”

The House bill’s summary says that the Joint Committee on Taxation estimates that the provision would cost taxpayers $2.1 billion from 2018 to 2027. A Ways and Means spokeswoman and a Joint Committee on Taxation staffer did not immediately explain how the committee had calculated the cost.

The release of the tax bill was not the first time the Johnson Amendment has grabbed the spotlight this year. President Donald Trump issued an executive order in May saying religious organizations could engage more in elections without fear of losing their tax-exempt status.

James Bopp Jr., a well-known conservative lawyer, said in May that he, like other social conservatives, opposes the Johnson Amendment because it provides the IRS with loosely defined standards that can give the government an excuse to target certain groups based on their political agenda.

“Those kind of vague standards allow arbitrary enforcement and political viewpoint discrimination,” said Bopp, who favors campaign finance deregulation.