An atheist who has spent years trying to ban recitation of the Pledge of Allegiance in public schools is now challenging the national motto printed on U.S. currency.

Michael Newdow said Sunday that he planned to file a federal lawsuit this week asking for the removal of the national motto, “In God We Trust,” from U.S. coins and dollar bills. He claims it’s an unconstitutional endorsement of religion and “excludes people who don’t believe in God.”