The American Civil Liberties Union filed a lawsuit against the city of Slidell, Louisiana on Tuesday for displaying a painting of Jesus in its courthouse lobby.

The ACLU sued after the Slidell City Court refused to voluntarily remove the picture and a message below it that reads: "To Know Peace, Obey These Laws." The ACLU says the portrait — an image of Jesus presenting the New Testament — is a religious icon of the Eastern Orthodox branch of Christianity, reported The Associated Press. It claims the portrait violates the constitutional separation of church and state.

The suit was filed on behalf of an unidentified person who complained to the ACLU about the picture. The defendants in the suit are the city of Slidell, City Judge James Lamz and St. Tammany Parish, which partially funds the court, said the ACLU.

On Saturday, Lamz said he didn't believe the portrait violates the Constitution and the picture would stay up unless a federal judge ordered it removed, reported the AP.

Michael Johnson of the Alliance Defense Fund, a Christian civil rights group representing the city and parish, noted that the painting has been on display at the courthouse for nearly a decade.

Johnson noted that the U.S. Supreme Court has ruled that similar displays in public places are constitutional.