The Federal Energy Regulatory Commission (FERC) allocated the cost of the Grand Gulf 1 nuclear reactor among several jointly owned companies, including petitioner New Orleans Public Service, Inc. (NOPSI), that had agreed to finance the reactors construction and operation. NOPSI, which provides retail electrical service to New Orleans, then sought from respondent New Orleans City Council (Council), the local ratemaking body, a rate increase to cover the increase in its wholesale rates resulting from FERCs allocation of Grand Gulf costs. Although deferring to FERCs implicit finding that NOPSIs decision to participate in the Grand Gulf venture was reasonable, the Council determined that the costs incurred thereby should not be completely reimbursed through a rate increase because NOPSIs management was negligent in failing, after the risks of nuclear power became apparent, to diversify its supply portfolio by selling a portion of its Grand Gulf power. NOPSI filed a petition in state court for review of the Councils final rate order. In parallel federal proceedings in the District Court, NOPSI sought declaratory and injunctive relief on the ground that the Councils order was pre-empted by federal law under Nantahala Power & Light Co. v. Thornburg, 476 U.S. 953, which held that, for purpose of setting intrastate retail rates, a State may not differ from FERCs allocations of wholesale power by imposing its own judgment of what would be just and reasonable. The District Court concluded that it should abstain from deciding the suit under Burford v. Sun Oil Co., 319 U.S. 315, and Younger v. Harris, 401 U.S. 37. The Court of Appeals affirmed.

Held:

The District Court erred in abstaining from exercising jurisdiction. Pp. 358-373.

(a) The Burford abstention doctrine - under which federal equity courts must decline to interfere with complex state regulatory schemes in cases involving (1) difficult state-law questions bearing on policy problems of substantial public import, or (2) efforts to establish a coherent state policy regarding a matter of substantial public concern - is not applicable. This case does not involve a state-law claim, nor even an assertion that NOPSIs federal claims are in any way entangled in a skein of state law that must be unraveled before the federal case can [491 U.S. 350, 351] proceed. Because NOPSIs facial pre-emption claim may be resolved without venturing beyond the four corners of the Councils rate order, federal adjudication of the claim would not unduly intrude into state governmental process or undermine the States ability to maintain desired uniformity in the treatment of essentially local problems. Although NOPSIs alternative claim - that the rate orders nominal emphasis on NOPSIs failure to diversify its power supply was merely a cover for the determination that the original Grand Gulf investment was itself unwise - cannot be resolved on the face of the order, resolution of that claim does not demand significant familiarity with, and will not disrupt state resolution of, distinctively local facts or policies, since wholesale electricity is not bought and sold within a predominantly local market. Pp. 360-364.

(b) Nor is abstention appropriate under Younger, which held that, absent extraordinary circumstances, traditional equity concerns and principles of comity require federal courts to refrain from enjoining pending state criminal prosecutions. This Court has expanded Younger abstention beyond criminal proceedings, and even beyond proceedings in courts, but never to proceedings that are not "judicial in nature." The Council proceedings at issue here are not judicial in nature, since ratemaking, which establishes a rule for the future, is essentially a legislative act. See, e. g., Prentis v. Atlantic Coast Line Co., 211 U.S. 210, 226-227. Nor can the pr