Whenever the Attorney General has reason to believe that a State or political subdivision (a) has enacted or is seeking to administer any test or device as a prerequisite to voting in violation of the prohibition contained in section
of this title, or (b) undertakes to deny the right to vote in any election in violation of section
of this title, he may institute for the United States, or in the name of the United States, an action in a district court of the United States, in accordance with sections
, for a restraining order, a preliminary or permanent injunction, or such other order as he deems appropriate. An action under this subsection shall be heard and determined by a court of three judges in accordance with the provisions of section
and any appeal shall be to the Supreme Court.