Whenever any person has engaged or there are reasonable grounds to believe that any person is about to engage in any act or practice prohibited by section 2000a–2 of this title, a civil action for preventive relief, including an application for a permanent or temporary injunction, restraining order, or other order, may be instituted by the person aggrieved and, upon timely application, the court may, in its discretion, permit the Attorney General to intervene in such civil action if he certifies that the case is of general public importance. Upon application by the complainant and in such circumstances as the court may deem just, the court may appoint an attorney for such complainant and may authorize the commencement of the civil action without the payment of fees, costs, or security.