The Trump administration on Tuesday asked a federal appeals court to block a lower court’s order directing the Trump administration to provide due process to scores of Venezuelan immigrants who were deported without hearings to El Salvador in March under a wartime law.

The emergency request by the Justice Department, filed to the U.S. Court of Appeals for the District of Columbia, came one day before the administration was supposed to send the lower court judge its proposal for how to allow nearly 140 of the deported Venezuelans to challenge their expulsion. The men, accused of being members of a violent street gang called Tren de Aragua, are being held in a maximum-security Salvadoran prison.

The White House deported the men on March 15 on a series of flights, using a powerful 18th-century statute known as the Alien Enemies Act. That law, which has been used on only three occasions in U.S. history, is meant to be used in times of declared war or during an invasion by a foreign nation.

The fight over the Venezuelans is merely one of the many bitter battles that have pitted courts across the country against an administration that is aggressively seeking to deport as many as immigrants as possible through methods that have repeatedly strained the boundaries of the law. Time and again, judges have settled on a similar bottom line, saying that the immigrants must be afforded basic due process rights before being expelled from the country.

The proceeding in front of Judge James E. Boasberg, the chief judge in Federal District Court in Washington, was one of the first deportation cases to reach the courts and remains one of the hardest fought. The judge tried to stop the deportation flights carrying the Venezuelans shortly after they took off, but the administration went ahead anyway, prompting him to threaten Trump officials with contempt proceedings.

Ever since the men landed in El Salvador, their lawyers have been seeking another order to bring them back to the United States. And last week, Judge Boasberg gave them some of what they wanted, directing Trump officials in an outraged decision to give the men the due process they were denied, but leaving it up to the administration to offer an initial plan about how to carry out his instructions.