MR. JUSTICE STEWART delivered the opinion of the Court.

The Amalgamated Association of Street, Electric Railway and Motor Coach Employees of America, AFL-CIO (the Union) filed an amended petition with the National Labor Relations Board pursuant to § 9(c) of the National Labor Relations Act, requesting a representation election among the porters, janitors and maids working at four Florida bus terminals operated by the respondent (Greyhound). The amended petition designated the "employer" of the employees sought to be represented as Greyhound and Floors, Inc. The latter, a corporation engaged in the business of providing cleaning, maintenance and similar services to various customers in Florida, had contracted with Greyhound to provide such services at the four terminals in question.

At the Board hearing on the petition, the Union contended alternatively that the unit requested was appropriate as a residual unit of all unrepresented Greyhound employees at the four terminals — on the ground that Greyhound was at least a joint employer with Floors of the employees — or that the unit was appropriate because the employees comprised a homogeneous, distinct group. Greyhound and Floors claimed that the latter was the sole employer of the employees, and that the appropriate bargaining unit should therefore encompass all Floors' employees, either in all four cities in which the terminals are located, or in separate groups.

The Board found that while Floors hired, paid, disciplined, transferred, promoted and discharged the employees, Greyhound took part in setting up work schedules, in determining the number of employees required to meet those schedules, and in directing the work of the employees in question. The Board also found that Floors' supervisors visited the terminals only irregularly — on occasion not appearing for as much as two days at a time — and that in at least one instance Greyhound had prompted the discharge of an employee whom it regarded as unsatisfactory. On this basis, the Board, with one member dissenting, concluded that Greyhound and Floors were joint employers, because they exercised common control over the employees, and that the unit consisting of all employees under the joint employer relationship was an appropriate unit in which to hold an election. The Board thereupon directed an election to determine whether the employees desired to be represented by the Union.

Shortly before the election was scheduled to take place, Greyhound filed this suit in the United States District Court for the Southern District of Florida, seeking to set aside the decision of the Board and to enjoin the pending election. After a hearing, the court entered an order permanently restraining the election. 205 F. Supp. 686. Concluding that it had jurisdiction on the basis of this Court's decision in Leedom v. Kyne, 358 U.S. 184, the court held on the merits that the Board's findings were insufficient as a matter of law to establish a joint employer relationship, that those findings established, as a matter of law, that Floors was the sole employer of the employees in question, and that the Board had therefore violated the National Labor Relations Act by attempting to conduct a representation election where no employment relationship existed between the employees and the purported employer. The Court of Appeals affirmed, 309 F.2d 397, and we granted certiorari to consider a seemingly important question of federal labor law. 372 U.S. 964. We reverse the judgment of the Court of Appeals.

Both parties agree that in the normal course of events Board orders in certification proceedings under § 9(c) are not directly reviewable in the courts. This Court held as long ago as American Federation of Labor v. Labor Board, 308 U.S. 401, that the "final order[s]" made reviewable by §§ 10(e) and (f) in the Courts of Appeals do not include Board decisions in certification proceedings. Such decisions, rather, are normally reviewable only where the dispute concerning the correctness of the certification eventuates in a finding by the Board that an unfair labor practice has been committed as, for example, where an employer refuses to bargain with a certified representative on the ground that the election was held in an inappropriate bargaining unit. In such a case, § 9(d) of the Act makes full provision for judicial review of the underlying certification order by providing that "such certification and the record of such investigation shall be included in the transcript of the entire record required to be filed" in the Court of Appeals.

That this indirect method of obtaining judicial review imposes significant delays upon attempts to challenge the validity of Board orders in certification proceedings is obvious. But it is equally obvious that Congress explicitly intended to impose precisely such delays. At the time of the original passage of the National Labor Relations Act in 1935, the House Report clearly delineated the congressional policy judgment which underlay the restriction of judicial review to that provided for in § 9(d):

"When an employee organization has built up its membership to a point where it is entitled to be recognized as the representative of the employees for collective bargaining, and the employer refuses to accord such recognition, the union, unless an election can promptly be held to determine the choice of representation, runs the risk of impairment of strength by attrition and delay while the case is dragging on through the courts, or else is forced to call a strike to achieve recognition by its own economic power. Such strikes have been called when election orders of the National Labor Relations Board have been held up by court review."

And both the House and the Senate Reports spelled out the thesis, repeated on the floor, that the purpose of § 9(d) was to provide "for review in the courts only after the election has been held and the Board has ordered the employer to do something predicated upon the results of the election." Congressional determination to restrict judicial review in such situations was reaffirmed in 1947, at the time that the Taft-Hartley amendments were under consideration, when a conference committee rejected a House amendment which would have permitted any interested person to obtain review immediately after a certification because, as Senator Taft noted, "such provision would permit dilatory tactics in representation proceedings."

In light of the clear import of this history, this Court has consistently refused to allow direct review of such orders in the Courts of Appeals. American Federation of Labor v. Labor Board, supra. In two cases, however, each characterized by extraordinary circumstances, our decisions have permitted district court review of orders entered in certification proceedings. In Leedom v. Kyne, 358 U.S. 184, despite the injunction of § 9(b)(1) of the Act that "the Board shall not (1) decide that any unit is appropriate . . . if such unit includes both professional employees and employees who are not professional employees unless a majority of such professional employees vote for inclusion in such unit," the Board — without polling the professional employees — approved as appropriate a unit containing both types of employees. The Board conceded in the Court of Appeals that it "had acted in excess of its powers and had thereby worked injury to the statutory rights of the professional employees." 358 U.S., at 187. We pointed out there that the District Court suit was "not one to `review,' in the sense of that term as used in the Act, a decision of the Board made within its jurisdiction. Rather it is one to strike down an order of the Board made in excess of its delegated powers and contrary to a specific prohibition in the Act." 358 U.S., at 188. Upon these grounds we affirmed the District Court's judgment setting aside the Board's "attempted exercise of [a] power that had been specifically withheld." 358 U.S., at 189. And in McCulloch v. Sociedad Nacional, 372 U.S. 10, in which District Court jurisdiction was upheld in a situation involving the question of application of the laws of the United States to foreign-flag ships and their crews, the Court was careful to note that "the presence of public questions particularly high in the scale of our national interest because of their international complexion is a uniquely compelling justification for prompt judicial resolution of the controversy over the Board's power. No question of remotely comparable urgency was involved in Kyne, which was a purely domestic adversary situation. The exception recognized today is therefore not to be taken as an enlargement of the exception in Kyne." 372 U.S., at 17.

The respondent makes no claim that this case is akin to Sociedad Nacional. The argument is, rather, that the present case is one which falls within the narrow limits of Kyne, as the District Court and the Court of Appeals held. The respondent points out that Congress has specifically excluded an independent contractor from the definition of "employee" in § 2(3) of the Act. It is said that the Board's finding that Greyhound is an employer of employees who are hired, paid, transferred and promoted by an independent contractor is, therefore, plainly in excess of the statutory powers delegated to it by Congress. This argument, we think, misconceives both the import of the substantive federal law and the painstakingly delineated procedural boundaries of Kyne.

Whether Greyhound, as the Board held, possessed sufficient control over the work of the employees to qualify as a joint employer with Floors is a question which is unaffected by any possible determination as to Floors' status as an independent contractor, since Greyhound has never suggested that the employees themselves occupy an independent contractor status. And whether Greyhound possessed sufficient indicia of control to be an "employer" is essentially a factual issue, unlike the question in Kyne, which depended solely upon construction of the statute. The Kyne exception is a narrow one, not to be extended to permit plenary district court review of Board orders in certification proceedings whenever it can be said that an erroneous assessment of the particular facts before the Board has led it to a conclusion which does not comport with the law. Judicial review in such a situation has been limited by Congress to the courts of appeals, and then only under the conditions explicitly laid down in § 9(d) of the Act.

Accordingly, the judgment of the Court of Appeals is reversed and the case is remanded for further proceedings consistent with this opinion.

It is so ordered.

MR. JUSTICE DOUGLAS dissents.