Authorities in Maryland and the District of Columbia say they intend to file a lawsuit Monday against President Trump, alleging he violated anti-corruption clauses in the Constitution—the first case of its kind filed by government entities. D.C. Attorney General Karl A. Racine and Maryland Attorney General Brian Frosh say Trump has breached his oath to surrender control of his business and violated the emoluments clause that forbids an acting leader from accepting payments from a foreign government. While the Justice Department concluded last week that Trump was not in violation of that clause as part of a separate lawsuit, Racine and Frosh intend to take the argument further by demanding the release of Trump’s tax returns to show the extent of his business with foreign countries. “We’re getting in here to be the check and balance that it appears Congress is unwilling to be,” Racine told The Washington Post on Sunday. “We’re bringing suit because the president has not taken adequate steps to separate himself from his business interests.” While Trump announced in January that he would shift his business assets into a trust managed by his sons, Racine and Frosh say there is not enough proof that Trump is putting the country before his business interests. The lawsuit singles out the Trump International Hotel as a possible conflict of interest. The hotel opened near the White House last year and almost immediately saw an influx of foreign ambassadors, some of whom seemed to be giving the hotel their business in order to curry favor with the president, The Washington Post reported at the time.