The district courts of the United States shall have jurisdiction of such actions which shall be heard and determined by a court of three judges in accordance with the provisions of section
2284 of title
28 and any appeal shall lie to the Supreme Court. It shall be the duty of the judges designated to hear the case to assign the case for hearing at the earliest practicable date, to participate in the hearing and determination thereof, and to cause the case to be in every way expedited.