A leading group that opposes same-sex marriage is urging U.S. Supreme Court Justice Ruth Bader Ginsburg to recuse herself from the landmark cases that could decide whether such marriages must be permitted under the Constitution.

The National Organization for Marriage’s amicus brief in the cases set for argument April 28 criticized Ginsburg for suggesting in a February press interview that increased public acceptance of gays makes it “doubtful” that a ruling in favor of same-sex marriage “wouldn’t be accepted.”