MADISON, Wis. (November 15, 2012)--A Madison, Wis.-based group of atheists and agnostics argues in a federal lawsuit filed Wednesday that the Internal Revenue Service is violating the U.S. Constitution by allowing tax-exempt churches and religious organizations to get involved in political campaigns.

The Freedom from Religion Foundation filed the lawsuit in U.S. District Court in Madison.

It cites full-page ads run this fall in the New York Times and other newspapers by the Billy Graham Evangelistic Association and a letter that Illinois Bishop Daniel Jenky required to be read in churches the weekend before the presidential election.

The lawsuit argues that not enforcing the law prohibiting tax-exempt religious organizations from electioneering results in preferential treatment not provided to other tax-exempt organizations, including the Freedom from Religion Foundation.