The Jewish resettlement agency HIAS has filed a lawsuit challenging the constitutionality of President Donald Trump’s temporary ban on refugees.

The complaint, filed Tuesday by lawyers from the American Civil Liberties Union in U.S. District Court in Maryland, alleges that the order violates the Constitution by discriminating against one religion and favoring others. Trump’s order specifically gives preference to persecuted religious minorities once the refugee resettlement program is resumed.

“As an organization that has long partnered with the U.S. government, litigation is unprecedented for HIAS, but we feel we have no other choice,” HIAS President Mark Hetfield said in a statement. “We cannot remain silent as Muslim refugees are turned away just for being Muslim, just as we could not stand idly by when the U.S. turned away Jewish refugees fleeing Germany during the 1930s and 40s. Our history and our values, as Jews and as Americans, require us to fight this illegal and immoral new policy with every tool at our disposal — including litigation.”

The order, signed by Trump on Jan. 27, temporarily halts the U.S. refugee resettlement program for 120 days, and suspends refugee resettlement for Syrian refugees indefinitely. The order is already the subject of federal litigation after a judge in Washington state issued a temporary stay. That ruling is currently under appeal.

HIAS, the former Hebrew Immigrant Aid Society, is a 135-year-old Jewish agency that assists refugees and asylum seekers based in Maryland.