An Act to improve judicial machinery by amending the requirement for a three-judge court in certain cases, and for other purposes.

Repeals the provisions of Federal judicial procedure which require that injunctions against enforcement of Federal and State statutes upon the ground of unconstitionality be heard and determined by a three-judge district court. (Repeals 28 U.S.C. 2281, 2282)

Provides that a district court of three judges shall be convened when required by Act of Congress, or when an action is filed challenging the constitionality of the apportionment of congressional districts or the apportionment of any statewide legislative body.

Makes provisions for the composition and procedure of any three-judge court required to be convened under this Act.

States that any action, suit, or proceeding in a court of the United States to which a State or any agency, officer, or employee thereof is not a party, wherein the constitutionality of any statute of that State affecting the public interest is drawn in question, the court shall certify such fact to the attorney general of the State, and shall permit the State to intervene for presentation of evidence, if evidence is otherwise admissible in the case, and for argument on the question of constitutionality. (Amends 28 U.S.C. 2284, 2403)