OPINION OF THE COURT
A 1938 zoning ordinance in the Pennsylvania borough of Fox Chapel providing for a minimum lot size of three acres was amended in 1964 to permit lots of two acres if drawn from a nine-acre tract. Appellant owns a parcel of 4.2568 acres. He contends that the ordinance and its amendment prevent his lawful utilization of his land and thus amount to an unconstitutional taking under the Fifth and Fourteenth Amendments. In the district court he unsuccessfully sought a declaratory judgment that the ordinances are unconstitutional. The court granted defendant’s motion to dismiss on the ground “that the cause of action was not a case or controversy ripe for judicial determination in that plaintiff has not exhausted his specific administrative and statutory remedies.” *214In the view we take of this case, it becomes necessary only to discuss whether appellant’s complaint presented an “actual controversy” under the Federal Declaratory Judgment Act, 28 U.S.C. § 2201.1
Statutory jurisdiction in these proceedings is based on diversity of citizenship, 28 U.S.C. § 1332. The Declaratory Judgment Act itself “is procedural only,” Aetna Life Ins. Co. v. Haworth, 300 U.S. 227, 57 S.Ct. 461, 81 L.Ed. 617 (1937);2 by the Act, “Congress enlarged the range of remedies available in the federal courts but did not extend their jurisdiction,” Skelly Oil Co. v. Phillips Petroleum Co., 339 U.S. 667, 671, 70 S.Ct. 876, 879, 94 L.Ed. 1194 (1950). Though statutory jurisdiction be present, however, a further jurisdictional inquiry is required to determine whether an “actual controversy” exists. The “word ‘actual’ is one of emphasis rather than of definition,” Aetna, supra, 300 U.S. at 240, 57 S.Ct. at 463. The “controversy” is required by the Constitution, and the statutory language is merely a restatement of the Article III mandate.3
*215Although this inquiry has commanded the attention of the Supreme Court both before4 and since the passage of the Federal Declaratory Judgment Act, the standards by which cases and controversies are distinguished from claims premature or insufficiently adverse are not susceptible of ready application to a particular ease. The considerations, while catholic, are not concrete.5 The Supreme Court itself is not unaware of this problem of definition. In a review of the proceedings after remand in Zwickler v. Koota, 389 U.S. 241, 88 S.Ct. 391, 19 L.Ed.2d 444 (1967), the Court held that because Zwickler’s Congressional candidate, for whom he desired to distribute literature in contravention of the questionable state statute, had, in the interim, been elected to a fourteen year term as a state judge, the First Amendment issue was mooted, and hence no actual controversy existed at the time of the hearing on remand. In Golden v. Zwickler, 394 U.S. 103, 108, 89 S.Ct. 956, 959-960, 22 L.Ed.2d 113 (1969), the Court observed:
The difference between an abstract question and a “controversy” contemplated by the Declaratory Judgment Act is necessarily one of degree, and it would be difficult, if it would be possible, to fashion a precise test for determining in every ease whether there is such a controversy. Basically, the question in each case is whether the facts alleged, under all the circumstances, show that there is a substantial controversy, between parties having adverse legal interests, of sufficient immediacy and reality to warrant the issuance of a declaratory judgment. Maryland Casualty Co. v. Pacific Coal & Oil Co., 312 U.S. 270, 273, 61 S.Ct. 510, 512, 85 L.Ed. 826 (1941).
The Court has, however, continually emphasized the substantial degree of specificity required in declaratory judgment actions. In United Public Workers v. Mitchell, 330 U.S. 75, 89, 67 S.Ct. 556, 564, 91 L.Ed. 754 (1947), in refusing to pass on the propriety of contemplated political activity by government employees challenging the Hatch Act, the Court held that abstract issues do not invoke the jurisdiction of the courts:
As is well known the federal courts established pursuant to Article III of the Constitution do not render advisory opinions. For adjudication of constitutional issues “concrete legal issues, presented in actual cases, not abstractions” are requisite. This is as true of declaratory judgments as any other field.
In Poe v. Ullman, 367 U.S. 497, 81 S.Ct. 1752, 6 L.Ed.2d 989 (1961), the Court refused the request of two women and a physician to have declared unconstitutional Connecticut’s proscription of the use or the dissemination of information concerning the use of birth control devices. The Court cautioned that federal judicial power “is to be exercised to strike down legislation, whether state or federal, only at the instance of one who is himself immediately harmed, or immediately threatened with harm, by the challenged action.” Id. at 504, 81 S.Ct. *216at 1756. Thereafter, the litigants accepted the dare implicit in Mr. Justice Frankfurter’s opinion. They opened birth control clinics in New Haven, Connecticut, were arrested, and again posed the constitutional question. The Court met the issue squarely and declared the statute unconstitutional, Griswold v. Connecticut, 381 U.S. 479, 85 S.Ct. 1678, 14 L.Ed.2d 510 (1965).6
Similarly, the Court dismissed as premature a request by alleged members of the Communist Party that a statute requiring registration statements by the Party on a form prescribed by the Attorney General be declared unconstitutional. In Communist Party of United States v. Subversive Activities Control Board, 367 U.S. 1, 106, 81 S.Ct. 1357, 1416, 6 L.Ed. 2d 625 (1960), the Court ruled that the mere promulgation of the regulation was not enough: “The duties imposed by those provisions will not arise until and unless the Party fails to register. At this time their application is wholly contingent and conjectural.”7 When the members subsequently appealed from an order directing them to register under the Act, however, the Court ruled that a declaratory judgment properly would lie. Albertson v. Subversive Activities Control Board, 382 U.S. 70, 86 S.Ct. 194, 15 L.Ed.2d 165 (1965).
Professor Wright has synthesized the teachings of the foregoing cases and others:8
The Supreme Court has indicated a very marked reluctance to have important issues of public law resolved by declaratory judgments. It has said that declaratory judgment procedures should not be used to preempt and prejudge issues that are committed for initial decision to an administrative body or special tribunal, and warned against grant of a declaratory judgment involving an important question of public law on the basis of a sparse and inadequate record. The Court has also said that questions of scope and constitutionality of legislation must not be decided “in advance of its immediate adverse effect in the context of a concrete case.” [International Longshoremen’s and Warehousemen’s Union v. Boyd, 347 U.S. 222, 224, 74 S.Ct. 447, 98 L.Ed. 335 (1954)]. *217(Footnotes omitted, emphasis supplied.) Wright, Law of Federal Courts § 100 at 449 (2d Ed. 1970).
Applying the foregoing principles to the ease before us, we hold that plaintiff has failed to establish a case or controversy of sufficient concreteness or immediacy to invoke federal jurisdiction. Appellant’s complaint was filed six years after the passage of the amended ordinance and thirty-two years after the original ordinance was enacted. He challenges both ordinances because they allegedly effect an unconstitutional taking of his land.
Beyond this, the complaint tells us little. Although appellant, a Florida domiciliary, apparently does not desire the premises for his own residential purposes, we are not told whether the thrust of his constitutional argument is directed against (1) the restriction for residential purposes only, (2) the original three-acre lot minimum created in the 1938 ordinance, (3) the 1964 amendment which permits, under certain circumstances, two-acre mínimums, or (4) any restriction as to minimum lot size.9
The complaint does not tell us when appellant became the owner of the premises. It does reveal that he voluntarily and gratuitously deeded 4.9532 acres of his original tract on September 27, 1968, to the borough for public park purposes, indicating that subsequent to the amended ordinance of 1964, the tract in question consisted of 9.21 acres and was owned by appellant. Further, the complaint does not disclose whether he requested and was refused a building permit, or, if buildings have been erected, whether he has been denied occupancy. There is no allegation of a past, present, or future threat by an officer of the borough constituting an interference with his use of the premises. From the complaint, we cannot decide whether he is arguing that the ordinances are unconstitutional as applied to him, certain other owners, or to all borough property owners.
The vagueness of this complaint exacerbates the difficulty any court would have in fashioning relief at this time. Indeed, it is extremely doubtful that a Pennsylvania state court would have entertained such a challenge to the zoning ordinances under the judicial review provisions of the Municipal Planning Code, Act of July 31, 1968, P.L.No. 247, 53 Purd.Stat.Anno. §§ 10101 et seq., with a pleading so devoid of concrete complaint. While it is true that the Code provides that no application for a subdivision approval or a building permit is necessary when the challenge is “addressed solely to a minimum lot size or maximum density requirement,” § 10801, it is essential that the complainant, in attacking the lot size or density requirement, demonstrate a specific restriction on the use of his land by an agency of the municipality or an officer thereof. We interpret the Code to provide the property owner with an efficient, inexpensive method of testing an ordinance without incurring the preliminary expenses of preparing plot and construction plans and other prerequisites normally required for a building permit application, or of preparing an engineering survey normally accompanying a request for subdivision approval. Nonetheless, it is essential that there be an *218attack on the zoning ordinance and a refusal of relief by the municipality before there may be a proper challenge to the constitutionality of “a minimum lot size or maximum density requirement” under the Code. This conclusion is compelled by an analysis of those provisions of the Code which limit judicial review to “appeals from the decisions of the board of zoning appeals and appeals upon reports of the board in proceedings to challenge the validity of any" ordinance or map.” § 11001.
Reinforcing this interpretation is the recent decision of Roeder v. Borough Council of Hatfield, 439 Pa. 241, 266 A. 2d 691 (1970) in which the court held that an appeal challenging the constitutionality of a borough zoning ordinance was premature and would not be ripe for adjudication until “action is taken pursuant to MPC, § 801 [53 Purd.Stat. Anno. § 10801].” Moreover, Roeder specifically required a “case or controversy ripe for judicial intervention * * * regardless whether the premature attack is by an action in equity or through the administrative framework.” Id. at 695.
At all events, irrespective of the treatment this complaint would receive in a state court, a state legislature cannot redefine a case or controversy under the federal constitution; it cannot redraw the jurisdictional metes and bounds of the federal courts. We are less persuaded by the bare assertion that jurisdiction would lie in the state courts than by the conclusion that because “[t]he pleadings failed to show a definite purpose on the part of the owners to use the lot for any purpose forbidden by either ordinance, * * * the case [does] not present an ‘actual controversy’ within the meaning of the Federal Declaratory Judgment Statute.” West v. Bank of Commerce and Trusts, 153 F.2d 566, 568 (4 Cir. 1946).
To use the formulation of the distinguished scholars, Hart and Weehsler, we are here presented with a “doubly contingent situation”: It is certain neither that appellant would be denied the use he desires of his real estate, nor that sanctions would be imposed upon him if he did.10
Plaintiff’s reliance on Lerner v. Town of Islip, 272 F.Supp. 664 (E.D.N.Y. 1967), is misplaced. In denying a motion to dismiss a challenge to a local zoning ordinance, Lerner held merely that the doctrine of abstention in no way precluded a federal court from reviewing the application of a local zoning ordinance to the property of an allegedly aggrieved landowner. No question of ripeness or immediacy was raised. Our holding is neither consistent with nor contrary to that in Lerner.11 Indeed in the view we take of this action, the absence of a case or controversy prohibits us from passing on the merits of plaintiff’s challenge to the Fox Chapel ordinance or deciding the propriety of a federal court to entertain such a challenge.
We conclude that the district court did not err in holding that the complaint did *219not state an actual controversy within the meaning of the Federal Declaratory Judgment Act.
The judgment of the district court will be affirmed.