delivered the opinion of the Court.

Respondent is a nonprofit, educational corporation organized under the laws of-the District of Columbia as “Protestants and Other Americans United for Separation of Church and State.” Its purpose is to defend and maintain religious liberty in the United States by the dissemination of knowledge concerning the constitutional principle of the separation of church and State. In 1950, the Internal Revenue Service issued a ruling letter that respondent qualified as a tax-exempt organization under the predecessor provision to § 501 (c) (3) of the Internal Revenue Code of' 1954 (the Code), 26 U. S. C. § 501 (c) (3).1 As a result, the Service treated contributions to respondent as charitable deductions under the predecessor provision of § 170 (c) (2) of the Code, 26 U. S. C. § 170 (c)(2).2 This situation continued unchanged until *755April 25, 1969, when the Service issued a ruling letter revoking the 1950 ruling on the ground that respondent had.violated §§ 501 (c)(3) and 170 (c)(2)(D) by devoting a substantial part of its activities to attempts to influence legislation. Shortly thereafter, the Service issued another ruling letter exempting respondent from income taxation as a “social welfare1’ organization under Code § 501 (c) (4), 26 U. S. C. § 501 (c) (4) .3 The effect of this change in status was to render respondent liable for unemployment (FUTA) taxes under Code § 3301, 26 U. S. C. § 3301,4 and to destroy its eligibility for tax-deductible contributions under § 170.

*756Because the 1969 ruling letter caused a substantial decrease in its contributions, respondent and two of its benefactors initiated the instant action in the United States District Court for the District of Columbia on July 30, 1970.5 They sought a declaratory judgment that the Service’s administration of the lobbying proscriptions of §§501 (c)(3) and 170 was erroneous or unconstitutional6 and injunctive relief requiring rein*757statement of respondent’s § 501 (c)(3) ruling letter. Because their objections to the Service’s action included a facial challenge to the constitutionality of federal statutes,7 they also requested the convening of a three-judge district court pursuant to 28 U. S. C. § 2282.

The Service moved to dismiss the action, principally on the ground that the exception in the Declaratory Judgment Act for cases “with respect to Federal taxes,” 8 and the_prohibition in the Anti-Injunction Act against suits “for the purpose of restraining the assessment or collection of any tax,”9 ousted the court of subject-*758matter jurisdiction. The District Court accepted this argument, refused to convene a three-judge court, and dismissed the complaint in an unpublished order filed March 9, 1971. The United' States Court of Appeals for the District of Columbia Circuit affirmed the dismissal insofar as it pertained to the individual plaintiffs, but it reversed as to respondent and remanded the case to the District Court with instructions to convene a three-judge court. “Americans United” Inc. v. Walters 155 U. S. App. D. C. 284, 477 F. 2d 1169 (1973). The Service petitioned for review, and. we granted certiorari. 412 U. S. 927 (1973). We reverse.

In our opinion in Bob Jones University v. Simon, ante, p. 725, we examined the meaning'of the Anti-Injunction Act and its interpretation in prior opinions of this Court, and we reaffirmed our adherence to the two-part test announced in Enochs v. Williams Packing & Navigation Co., 370 U. S. 1 (1962). To reiterate, the Court in Williams Packing únanimously held that a pre-enforcement injunction against the. assessment or collection of taxes may be granted only (i) “if it is clear that under no circumstances could the Government ultimately prevail . . . id., at 7; and (ii) “if equity jurisdiction otherwise exists.” Ibid. Unless' both conditions are met, a suit for preventive injunctive relief must be dismissed.

In the instant case the Court of Appeals-recognized Williams Packing as controlling precedent for responds ent’s individual coplaintiffs and affirmed the dismissal of the súit as to them. 155 U. S. App. D. C., at 292, 477 F. 2d, at 1177. The court held that the relief requested by the, individual plaintiffs “relate [d] directly to the assessment and collection of taxes” and that the allegations of *759infringements of constitutional rights were “to no avail” in overcoming the barrier of § 7421 (a). Id.; at 291, 477 F. 2d, at 1176. The court also recognized that respondent could not satisfy the Williams Packing criteria, id., at 298, 477 F. 2d, at 1183, but concluded that respondent’s suit was without the scope of the Anti-Injunction Act and therefore. not subject to the Williams Packing test.10

The court’s conclusion with regard to respondent rested on the confluence of several factors. One was the constitutional nature of respondent’s cláims. As the court noted, the thrust of respondent’s argument is not that it qualifies for a § 501 (c) (3) exemption under existing law but rather that that provision’s “substantial part” test and proscription against efforts to influence legislation are unconstitutional. Id., at 293, 477 F. 2d, at 1178. Obviously, this observation could not have beendispositive to the Court of Appeals, for this factor does not differentiate respondent, which was allowed to sue, from the individual coplaintiffs, who likewise pressed constitutional claims but who were dismissed from the action. Furthermore, decisions of this Court , make it unmistakably clear that the constitutional nature of a taxpayer’s claim, as distinct from its probability of success, is of no consequence under the Anti-Injunction Act. E. g., *760Bailey v. George, 259 U. S. 16 (1922); Dodge v. Osborn, 240 U. S. 118 (1916).

The other three factors identifiéd by the Court of Appeals are equally unpersuasive. . First, the court noted that respondent “does not seek in this lawsuit to enjoin the assessment or collection of its own taxes.” 155 U. S. App. D. C., at 292, 477 F. 2d, at 1177. Because respondent volunteered to pay FUTA taxes even if it obtained an injunction restoring its •§ 501 (c) (3) status, this observation, we may assume, is correct. It is also irrelevant. •Section 7421 (a) does not bar merely a taxpayer’s attempt to enjoin the collection of his own taxes. Rather, it declares in sweeping terms that “no suit for the purpose of restraining the assessment or collection of any tax shall be maintained in any court by any person, whether or not such person is the person against whom such tax was assessed.” 11 Thus a suit to enjoin the assessment or collection of anyone’s taxes triggers the literal terms of § 7421 (a). ■

Perhaps the real point of the court’s observation about respondent’s taxes was to ■ set the stage for its more pertinent conclusion that restraining the assessment or collection of taxes was “at best a collateral effect” of respondent’s action and that this suit arose “in a posture removed from a restraint on assessment or collection.” 155 U. S. App. D. C., at 294, 477 F. 2d, at 1179. We disagree. Under any reasonable construction of the statutory term “purpose,” the objective of this suit was to restrain the assessment and collection of taxes from respondent’s contributors. The obvious *761purpose of" respondent’s action was to restore advance assurance that donations to it would qualify as charitable deductions under § 170 that would reduce the level of taxes of its donors.12 Indeed, respondent would not be interested in. obtaining the declaratory and injunctive relief requested if that relief did not effectively restrain the taxation of its contributors. Thus , we think it circular to conclude, as did the Court of Appeals, that respondent’s “primary design’’ was not “to remove the burden of taxation from those presently contributing but rather to avoid the disposition of contributed funds away from the corporation.” Ibid. The latter goal is merely a restatement of the former and can be accomplished only by restraining the assessment and collection of a tax in contravention of § 7421 (a).

Finally, -the Court of Appeals emphasized that respondent had no “alternate legal remedy in the form of adequate refund litigation ....” Id., at 295, 477 F. 2d, at 1180. The court recognized, of course, that respondent does have an opportunity to litigate its claims in an action for refund of FUTA taxes but dismissed this alternative with the statement that “it is subject to certain conditions and, we feel, is so far removed from the mainstream of the action and relief sought as to hardly be considered adequate.” Id., at 294 n. 13, 477 F. 2d, at 1179 n. 13. The import of these comments is unclear. If they are. taken to mean that a refund action is, as a practical matter, inadequate to avoid the decrease in respondent’s contributions for the interim between the withdrawal of § 501 (c) (3) status and the final adjudication of its en*762titlement to that exemption, they are certainly accurate. This, however, is only'a statemént of irreparable injury, which is the essential prerequisite.for injunctive relief, under traditionál equitable standards and only one part of the Williams Packing test. As noted in Bob Jones, ante, at 745-746, allowing injunctive relief on the basis of this showing alone would render § 7421 (a), quite meaningless.

If, on the other hand, the court’s comments about the inadequacy of a refund action for FUTA taxes are .interpreted to mean that respondent lacks an opportunity to have its claims finally adjudicated by a court of law, we think they are inaccurate. Respondent’s liability for FUTA taxes hinges on precisely the same legal issue as - does its eligibility for tax-deductible contributions under § 170, namely its entitlement to § 501 (c)(3) status. And respondént will have a full opportunity to litigate the legality of the Service’s withdrawal of respondent’s §501 (c)(3) ruling letter in a refund suit following the payment of FUTA taxes. E. g., Christian Echoes National Ministry, Inc. v. United States, 470 F. 2d 849 (CA10 1972), cert. denied, 414 U. S. 864 (1973).13

*763We therefore conclude that there are no valid reasons to distinguish this case from Williams Packing for purposes of § 7421 (a) or to' exempt respondent’s suit from the dual requirements enunciated in that case.14 The judgment is reversed.

It is so ordered.

dissenting.

Finding myself in solitary dissent in this “tax” case, I am somewhat diffident about expressing views contrary to those the Court apparently has reached so easily. I do so only because I am disturbingly aware of the overwhelming power of the Internal Revenue Service. This power is such that its mere exercise often freezes tax status so as to endanger. the existence of philan-° thropic organizations and the public benefits they secure, merely because the path to judicial review is so discouragingly -long and expensive. I write primarily, therefore, to express what I feel is a. needed word of caution about governmental power where the means to challenge that power are unfavorable and unsatisfactory at best. •

*764I

“Americans United” Inc. (AU) is a District of Columbia nonprofit educational corporation organized in 1948. For almost 18 years AU was formally recognized by the Service as. exempt from federal income tax under § 501 (c) (3) of the Internal Revenue Code of 1954, 26 IT. S. C. §501 (c)(3),1 and its predecessor, § 101 (6) of the Internal Revenue Code of 1939.

On April 25, 1968, however, the Commissioner of Internal Revenue revoked AU’s letter-ruling exemption on the ground that the organization -no longer met the' requirements of § 501 (c) (3) and, instead, was an “action” organization, within the definition of Treasury Regulations §§ 1.501 (c)(3)-! (c)(3)(i) and (iv)^, in that a substantial part of its activities was devoted to the pursuit of objectives to influence legislation App. 7-10. The loss of its § 501- (c) (3) status, however; did not result *765in AU’s becoming subject to federal income tax. This was because AU qualified as a civic league or other prgahization to which § 501 (c) (4) has -application.2

The result, nevertheless, was distinctly adverse to AU in two respects. A contribution to the organization no longer was deductible-by the donor under §§170(a)(l) and (c)(2)(D) of the 1954 Code, 26 U. S.. C. §§170 (a)(1) and (c)(2)(D), the latter of which closely parallels but is not identical with § 501 (c) (3). As a matter of much less concern, AU also became subject to federal unemployment tax under § 3301 of the Code, 26 U. S. C. § 3301, for exemption therefrom for § 501 organizátions is limited to those that qualify under §-501 (c)(3). § 3306 (c) (8) of the 1954 Code,'26 U. S. C'. § 3306 (c)'(8).3 AU has paid federal unemployment taxes,4' and has stipulated that it will continue to do so.

*766As a result of the revocation of its § 501 (c)(3) status, contributions by donors to AU declined sharply so that for the first time the organization was not able to raise enough funds to cover its expenses. AU and two of its benefactors then sought relief by the present suit.5 They have alleged that the substantiality test of §§ 501 (c) (3) and 170.(c)(2)(D) created an unconstitutional disparity between large and small organizations; that the Commissioner revoked AU's exemption ruling punitively; that *767it was unconstitutional to. penalize First Amendment activity in this manner; and that §501 (c) (3)’s “substantial” and “propaganda” standards were unconstitutionally vague. AU sought reinstatement on the IBS Cumulative List of Organizations so that contributions to it would be deductible by donors under §§ 170 (a)(1) and (c)(2)(D).

II

The Anti-Injunction Act, § 7421 (a) of the Code, 26 U. S. C. § 7421 (a), reads in part:

,“[N]o suit for the purpose of. restraining the assessment or collection of any tax shall be maintained in any court by any person, whether or not such person is the person against whom such tax was assessed.”

In considering § 7421 (a), a two-step analysis is necessary: (1) When does the statute apply? (2) When it is applicable, under what circumstances is an exception permitted? It seems to me that the Court overlooks the first question in order to apply mechanically the criteria for an exception to the application of § 7421 (a).

The threshold question, obviously, is whether the present litigation is a “suit for the purpose of restraining” any tax. It is. conceded that AU has no income tax liability. and will have none regardless of the outcome of this litigation. . AU has paid,, and will continue to pay, federal unemployment taxes. Its Assumption of FICA tax liability is frozen and cannot now be terminated.

It is in the context of this fixed and certain status as to all these federal taxes — income, unemployment, FICA — that “the purpose” of the present litigation, within the meaning of § 7421 (a), must be ascertained. AU. asserts that the purpose is to determine its charitable status so far as benefactors are concerned. Indeed, one *768surely must concede that, within the literal import of the statute’s words, the suit is not one “for the purpose of restraining . . . any tax.” It is, instead, a suit to assure the continuance of contributions utilized to sus-' tain AU’s operations.

I would not attribute to Congress, however, so simplistic a prohibition in § 7421 (a) as to enable an organization to circumvent the statutory barrier by a subjective protestation of the purpose for which an injunction is sought. In order to ascertain legislative intent, it is nepessary to consider effect as well as purpose and thús to bring objective criteriá into the analysis. See Recent Development, 73 Col. L. Rev. 1502, 1508-1510 (1973). '

In Bob Jones University v. Connolly, 472 F. 2d 903, 906 (1973), the Fourth Circuit concluded that when the withdrawal of an exemption “would ultimately result in potentially greater tax revenues,” thé obvious purpose of a suit to enjoin the withdrawal is. to prevent the assessment of tax, and § 7421 (a) would be applicable. Thus, “purpose” was equated with ultimate tax effect. Crenshaw County Private School Foundation v. Connally, 474 F. 2d 1185, 1188 (CA5 1973), pet. for cert. pending No. 73-170, has a similar focus. In the present ease the Court of Appeals took a different approach:

“The restraint upon assessment and collection is. at best a collateral effect of the action, the primary design not being to remove the burden of taxation from those presently contributing but rathu to avoid' the. disposition .of contributed funds away from the corporation.” 155 U. S. App. D. C. 284, 293-294, 477 F. 2d 1169, 1178-1179.

In. this view, applicability of the statute depends on the direct effect the relief sought would have on the plaintiff and not on--the system as a whole.

*769■ As has been noted, the result of the injunction sought here would not directly inhibit the collection of tax from AU. It is'also highly speculative what collateral effect, if any at all, the suit could possibly have on the federal revenue. If the assertion that AU’s contributions have dried up is to. be .accepted, as I suspect it must be, I would presume that its erstwhile contributors have found other objects for their bounty, that' is, other organizations whose names remain on the Service’s vitally important Cumulative List. When nothing more than possible collateral effect on the revenues is involved, the Court’s wide-ranging test of applicability of •§ 7421 (a), announced today, is, for me, too attenuated and too removed to be encompassed within the intendment of the statute’s phrase, “for the purpose of restraining the assessment or collection of any tax.”

In Enochs v. Williams Packing & Navigation Co., 370 U. S. 1 (1962), this Court observed that the object of §7421 (a) “is to withdraw jurisdiction from the . . . courts to entertain suits seeking injunctions prohibiting the collection of federal taxes,” and “to permit the United States to assess and collect taxes alleged'to be due without judicial intervention, and to require that the legal right to the disputed sums be determined in a suit for refund.” Id., at 5 and 7. There undoubtedly, is appropriate concern about the underlying danger “that a multitude of- spurious suits, or even of suits withj^ossible merit, would so interrupt the/free flow oi> reveñues as-to jeopardize the Nation’s fiscal stability. See, e. g., State Railroad Tax Cases, 92 U. S. 575, 613-614 (1876); Cheatham v. United States, 92 U. S. 85, 89 (1876). Certainly, precollection- suits could threaten planning and budgeting. But I do not -perceive how the injunction desired in this case interferes with the area of concern that is the subject of § 7421 (a). Any po*770tential ■ increase in revenues because donors no longer may contribute to AU and thereby obtain a § 170 (a) (1)-deduction is, at best, only minor and speculative and is neither significant, nor controlling. I, therefore,' would accept “direct effect on the plaintiff” as a component to be considered in the ascertainment of the true “purpose” of the suit, within the meaning and reach of § 7421.(a).

I do not wish to indicate disapproval of Williams Packing'. There a taxpayer sought' to enjoin the collection of faxes. As the basis for equitable jurisdiction, it asserted that it would.be thrown into bankruptcy if it were required to pay the taxes it challenged. The Court carefully noted that, there may. well be situations where “the central purpose of the Act is inapplicable and . . . the attempted collection may be enjoined.” 370 U. S., at 7. To be sure, the Court narrowly confined exceptions to § 7421 (a) to instances where the plaintiff would suffer irreparable injury and where it was “clear that under no circumstances could the Government ultimately prevail.” Ibid. If, however, this test is met, then the “manifest purpose” of the statute — to permit the collection of taxes without judicial intervention^ — is “inapplicable.” The Court thus made it .clear that there was an element, in addition to the traditional equity considerations, previously spelled out in Miller v. Standard Nut Margarine Co., 284 U. S. 498 (1932), that must be presr ent in order to avoid the proscription of the Anti-Injunction Act.'

Williams Packing, of course, on its facts, is clearly’ distinguishable from this case. There the purpose of the suit was directly to restrain the collection of social security and unemployment taxes allegedly past due from that taxpayer. Here the avowed purpose is not to restrain, tax collection but to assure ATI’s restoration to the Cumulative List. In Williams Packing it was the incidence of taxation that was challenged and the ir*771reparable injury of prospective payment of the tax was claimed as the equitable basis for the injunction. Nothing remotely resembling that is present here. To read Williams Packing as broadly-as the Court does today is to make § 7421 (a) more restrictive than the Court in Williams Packing or Congress intended. ' The result is that § 7421 (a) becomes an absolute bar to any and . all injunctions, irrespective of tax liability, of purpose or effect of the suit, or of the character of the Service’s action.

There is a further consideration. Arguably, where the challenged governmental action is not one intended to produce revenue but, rather, is one to accomplish a broad-based policy objective through the medium of fedéral taxation, the application of § 7421 (a) is inappropriate.6 *772Obviously, § 501 (c)(3) -is not designed tb raise money.7 Its purpose, rather, is' to. assure the existence of truly-philanthropic organizations and the continuation of the important public benefits they bestow.8

*773Another very1'important factor deserving.consideration in this context is the hazard of vesting in the Commissioner virtual'plenipotentiary power-over philanthropic organizations. Although there can be little question that .the Commissioner, under § 7805 (a) o.f the. Code, 26 U. S. C. 17805 (a), is properly vested with,broad powers to “prescribe all needful rules and regulations for the enforcement” of the tax laws, there is nothing, in .the Code that suggests that he must be fully insulated! from challenge when effectuating social policy.

- AU has charged unconstitutional treatment pursuant to an unconstitutional provision. These «re claims peculiarly within the province, of courts and not of the Executive’s administrative officers. : The Court’s opinion' makes clear that a claim of this kind is now precluded from judicial determination until such time as the Court concludes that the Government could not ultimately prevail on the merits. Unless' and until that conclusion is reached, the philanthropic organization is at -the mercy of the Commissioner for the period of time — usually a *774substantial one — it takes for a claim to be filed and to work its way through the adjudicative process in the guise of a refund suit with its myriad pitfalls. And even this route is possible only if the organization has a tax that has been paid.9 See Part III, infra.

The Court in Bob. Jones University, ante, at 729-730, acknowledges that “appearance on the Cumulative List is a prerequisite to successful fund raising for most charitable organizations.” The program of exemption by letter.ruling, therefore; is tantamount to a licensing procedure. If the Commissioner’s authority were limited by a clear statutory definition of § 501 (c)(3)’s require-: ment of “no substantial part/’ or by an objective definition of what is “charitable,” there would be less concern about possible. administrative abuse.10 But' where the philanthropic organization is concerned, there appears to be little to circumscribe the almost unfettered power of the Commissioner.11 This may be very well so long *775as one subscribes to the particular brand of social policy the Commissioner happens to be advocating at the time (a social policy the. merits of which I make nio attempt tQ evaluate), but application of our tax laws should not operate in so fickle a fashion. Surely, social policy in the first instance is a matter for legislative concern. To the extent these determinations are reposed in the authority of the Internal Revenue Service, they should have the 'system of checks and balances provided- by judicial review before an organization that, for years has been favored with an exemption ruling is imperiled by an allegedly unconstitutional change of- direction on the part of the Service.

When ah organization which has appeared on- the Cumulative List seeks to enjoin what it claims is its illegal removal from that List and has no direct income tax liability or a de minimis collateral liability, the injunction, in my view, should not be within the prohibition of §7421 (a).

111

Concluding, as I have, that § 7421 (a) is not a bar to an injunction by AU, the traditional equitable considera*776tions of irreparable injury and adequate alternative remedy must determine whether injunctive relief is appropriate. This is an inquiry independent of the question whether the Anti-Injunction Act applies, and is no different from the inquiry as to when injunctive relief is appropriate outside the tax field. See, for example, Public Service Comm’n v. Wycoff Co., 344 U. S. 237, 240-241 (1952); Beacon Theatres, Inc. v. Westover, 359 U. S. 500, 506-507 (1959). AU makes a vigorous and pressing- claim that it is and will be irreparably injured by the loss of contributions since donors no longer receive an income tax deduction, and that this loss is completely unrecoverable even were AU ultimately to prevail on the merits. The Court in its opinion, ante, at 761-762, seems to accept the fact of irreparable injury here, just as the Court of Appeals recognized its presence as virtually inevitable. 155 U. S. App. D. C., at 292, 477 F. 2d, at 1177. Even where it has been found that § 7421 (a) bars a suit, it has been recognized that revocation of exempt status is an irreparable injury that otherwise satisfies the condition for the granting of injunctive relief. See, for example, Bob Jones University v. Connally, 472 F. 2d, at 906.

In addition to irreparable injury, the plaintiff must show that he. has, no adequate remedy at law. Wilson v. Shaw, 204 U. S. 24, 31 (1907). The Commissioner suggests that a plaintiff organization usually has three alternative remedies, any one of which is adequate: an income tax refund suit, a federal unemployment tax or FICA tax refund suit, and an accommodation suit by a selected donor in the' form of testing- his claim to a charitable deduction_under §§170 (a)(1) and (c)(2)(D).

In- AU’s case the Commissioner, of course, cannot and does not contend that the income tax refund suit alternative is available. AU received § 501 (c) (4) status, upon *777revocation of its § 501 (c) (3) exemption, ánd it is not subject to federal income tax so long as it retains § 501 (c)(4) status. Whenever that alternative is available, .as in Bob Jones University, ante, p. 725, such availability not only indicates the existence of a remedy at law but that the direct effect of an injunction would be to restrain the collection of taxes.

■ An FICA tax refund suit is not available as an alternative to AU, since AU has made • its election under §3121 (k)(l)(A) and that election is now irrevocable. See n. 3, supra. Although AU conceivably might bring a refund suit for federal unemployment taxes,12 the real question, and a substantial one, is whether that remedy is adequate for AU and is an effective route for the determination of the issues involved. •

A suit for refund of federal unemployment tax, authorized under § 7422 of the Code, 26 U. S. C. § 7422, and with a period of limitations imposed by. § 6532 (a), is' directly geared to a determination of the technical *778aspects of FUTA liability and not to the larger constitutional issues. At most, the refund suit is an artificial vehicle to adjudicate questions other than entitlement to refund; its focus is on liability and not on. eligibility under §§ 170 (a)(1) and (c)(2)(D). It is most doubtful, also, that potential contributors would regard a favorable outcome in such, a suit as possessing the reliability of a favorable letter ruling. Assuming that.AU could litigate its constitutional claims in an FUTA.refund suit, see Christian Echoes National Ministry, Inc. v. United States, 470 F. 2d 849 (CA10 1972), cert. denied, 414 U. S. 864 (1973),13 there are other obstacles in its path.

The suit, for refund may not be maintained until a claim for refund has been filed. § 7422. The federal unemployment tax is imposed on an annual basis; thus, no refund can be claimed until the expiration of the year for which the tax is paid. Section 6532 (a)(1), as usual, precludes the suit until the claim is denied or six months have passed from the date of filing. Once suit is instituted, the Government has at least 60 days to answer the complaint. Under optimum conditions and with cooperation, the minimum period of time required to achieve the objective through the refund suit is one to two years from: the timé of revocation.14 This is the delay if the *779organization wins and no Government appeal is taken. If an appeal follows, the delay in ultimate resolution drags on. E. g., Christian Echoes, supra, where the ruling was revoked in 1966 and final judicial review wqs concluded only in 1973. While this is perhaps to be expected, and must be endured, in an ordinary tax refund suit, a delay of this magnitude defeats the adequacy of remedy when a philanthropic organization’s very existence is at stake.

There are still other hazards. When small sums are at issue, as with AU’s FUTA liability, the Government inadvertently or intentionally may concede the refund. This is not unlikely, for sound administration may not warrant the time and expense necessary to contest a claim of small amount when vital issues and conceivably profound precedents are at stake. Church of Scientology v. United States, 485 F. 2d 313 (CA9 1973), illustrates the Government’s effort to win dismissal of a case when a refund had been made. See also Mitchell v. Riddell, 402 F. 2d 842 (CA9 1968), appeal dismissed and cert. denied, 394 U. S. 456 (1969). Theie is little doubt that the Commissioner possesses the authority to make the refund and moot- the suit if he chooses not to litigate the underlying issues. Although I agree with the Commissioner *780that to do so in a situation like that in the instant case -would amount to bad faith, Brief for Petitioner 35 n. 25, it would be almost impossible for an organization to‘prove bad faith where, as here, the sum at issue is minimal and inadvertence' or sound administration could be a valid reason for the refund.

Additionally, there is a substantial question whether an organization’s eventual victory in a refund suit would accomplish its goal.. The Commissioner has asserted that “normal practice is to issue a favorable ruling upon the application of an organization which has prevailed in a court suit,” Reply Brief for Petitioner 34 — 35, n. 31. Still, the IRS Exempt Organizations Handbook states:

.“An organization which obtains a Tax Court or Federal coürt decision holding it to be exempt must file an exemption application and establish its right to exemption before the Service will recognize its exemption for years subsequent to those involved in the court decision.” Department of Treasury, Internal Revenue Manual, Part XI, c. (11) 671, ¶ 270.

Whatever the internal ..practice may be, the published procedures cast serious doubt on the adequacy of the refund suit to resolve the organization’s- urgent problem. The revenue ruling has prospective application, whereas a court determination operates retrospectively, to the extent the pleadings and proof and the applicable statute of limitations permit.15 Thus, the scope of relief available in a refund suit' is also uncertain. The orga*781nization is then faced with the- dilemma of choosing between a so-called pre-assessment suit, which the Court says it cannot bring, and a refund suit that decides little' more than the correctness of a particular year’s tax liability (which in this case has been paid and is of little or no concern).

.The staged suit by a “friendly” donor is the Commis•sioner’s other suggestion. The donor’s suit suffers the same time problems. The organization is off . the Cumulative List at least until the donor establishes his entitlement to a §§.170 (a)(1) and. (c) (2) (D) deduction. This suit also may be mooted. Moreover, litigation by the accommodating donor does not permit the organization to assert its rights and interests. Could the donor make the First Amendment and equal protection claims- that .AU seeks to have determined? Not only must AIT rely on a contributor to raise issues for. it, but it must find á donor who is-willing both to contribute and to undertake the task of litigation. This strains largesse to the extreme, particularly since the suit will subject the donor to routine .full audit of his own return.

L conclude that neither course is an adequate remedy for an' irreparably harmed organization to vindicate its .claims.16 ■ Thus, equitable relief in the form of an injunction is not inappropriate.

*782IY

The last issue is whether the amended complaint presented a substantial' constitutional question om the merits justifying the convening of a three-judge court under 28 U. .S. C. § 2282. The test was enunciated in Ex parte Poresky, 290 U. S. 30, 32 (1933), and restated in Goosby v. Osser, 409 U. S. 512, 518 (1973), and in Hagans v. Lavine, 415 U. S. 528, 542-543 (1974), The Court of Appeals in the present case said that “the possibility of success is- not so certain as to merit the Enochs exception with respect to § 7421 (a), yet not so frivolous or foreclosed as to merit denial of the § 2282 motion.” 155 U. S. App. D. C., at 298, 477 F. 2d, at 1183. Fd0/ not differ with that determination.

I, of course, imply no opinion on the merits of the underlying controversy.

. Since I cannot join the Court’s reversal of the Court of Appeals’ judgment, I respectfully dissent.