and the Attorney General believes the complaint is meritorious and certifies that the signer or signers of such complaint are unable, in his judgment, to initiate and maintain appropriate legal proceedings for relief and that the institution of an action will materially further the orderly achievement of desegregation in public education, the Attorney General is authorized, after giving notice of such complaint to the appropriate school board or college authority and after certifying that he is satisfied that such board or authority has had a reasonable time to adjust the conditions alleged in such complaint, to institute for or in the name of the United States a civil action in any appropriate district court of the United States against such parties and for such relief as may be appropriate, and such court shall have and shall exercise jurisdiction of proceedings instituted pursuant to this section, provided that nothing herein shall empower any official or court of the United States to issue any order seeking to achieve a racial balance in any school by requiring the transportation of pupils or students from one school to another or one school district to another in order to achieve such racial balance, or otherwise enlarge the existing power of the court to insure compliance with constitutional standards. The Attorney General may implead as defendants such additional parties as are or become necessary to the grant of effective relief hereunder.