dissents and filed a dissenting opinion at page 526 infra.
The Constitution of Maryland, Article III, § 52 (5a) mandates that the Governor of Maryland submit an annual budget and Budget Bill to the General Assembly containing “the total of all proposed appropriations and ... the total of all estimated revenues available to pay the appropriations, and the figure for total proposed appropriations shall not exceed the figure for total estimated revenues.” The section requires that the Budget Bill, as enacted, shall also be balanced, i.e., that “the figure for total estimated revenues always shall be equal to or to exceed the figure for total appropriations.”
On January 21,1976, the Governor submitted a budget and Budget Bill to the General Assembly in the amount of $3.6 billion for the fiscal year ending June 30, 1977. Included within it were estimated revenues of $74 million which would accrue to the State if during the 1976 legislative session the General Assembly enacted two lottery-related statutes proposed by the Governor. Also included were estimated revenues of $21 million which would become available to the State if the Congress of the United States extended the *523Federal Revenue Sharing program beyond its scheduled expiration date of December 31, 1976. None of the appropriations requested in the Budget Bill were contingent upon the passage of the proposed revenue-producing state or federal legislation. By an opinion dated February 23,1976, the Attorney General of Maryland found no constitutional infirmity in the inclusion of these estimated revenues in the budget.1 The Budget Bill was finally passed by the General Assembly on April 12, 1976. The proposed state legislation designed to produce the estimated revenues of $74 million was enacted by the General Assembly and signed into law by the Governor on May 4, 1976.
On July 26, 1976, the appellants, taxpayers and certain members of the General Assembly, sought a declaratory judgment that the inclusion of the contingent revenue sources in the Budget Bill, both as submitted and as finally enacted, violated the “balanced” budget requirements of § 52 (5a) of Article III of the Maryland Constitution. Specifically, it was alleged that the estimated revenues in question were “contingent revenue figures in that they require legislative approval as a condition precedent to their becoming [within the contemplation of § 52 (5a)] ‘estimated revenues available to pay the appropriations’ contained in the budget”; and that “Since these revenue figures are contingent revenues and not ‘estimated revenues available to pay the appropriations’ the Budget submitted by the Governor was not balanced.”
The case was heard on January 21, 1977, by the Circuit Court for Anne Arundel County (Beardmore, J.) on cross-motions for summary judgment. By an order filed on February 15, 1977, the court concluded that as long as the total proposed appropriations did not exceed the total estimated revenues, including revenues contingent upon the enactment of state or federal legislation, § 52 (5a) was not violated. An appeal was timely entered; we granted certiorari prior to decision in the case by the Court of Special Appeals. See Maryland Code (1974) Courts and Judicial Proceedings Article, § 12-201.
*524The appellants argue that it is the purpose of § 52 (5a) to avoid budget deficits and that consequently estimated revenues must actually be “available” at the time they are included in the budget by the Governor. They maintain that the constitutional provision cannot be interpreted to permit the Governor to use his intuition or political wisdom to balance the budget, and that to afford the word “available,” as used in § 52 (5a), a subjective, rather than an objective denotation, subjects the executive budget system to the very abuse that it was established to avoid. Appellants limit their constitutional attack on appeal to the estimated revenues included in the budget which were contingent upon the passage of the federal legislation.
The legislation extending the Federal Revenue Sharing program beyond December 31, 1976, upon which the Governor relied in submitting his estimated revenue figure of $21 million was enacted by the Congress of the United. States and approved by the President on October 13,1976. See State and Local Fiscal Assistance Amendments of 1976, Pub. L. No. 94-488, 90 Stat. 2341. Hence, the revenues estimated by the Governor, both state and federal totaling $95 million, which he included in his budget were in fact realized well before the Circuit Court for Anne Arundel County entered its declaratory decree.
It is, of course, well established that the existence of a justiciable controversy is a prerequisite to the maintenance of a declaratory judgment action. Harford County v. Schultz, 280 Md. 77, 371 A. 2d 428 (1977); Pr. George’s Co. v. Bd. of Trustees, 269 Md. 9, 304 A. 2d 228 (1973). Time and again, we have said that appellate courts do not sit to give opinions on abstract propositions or moot questions, and appeals which present nothing else for decision may be dismissed as a matter of course. State v. Ficker, 266 Md. 500, 295 A. 2d 231 (1972); Potts v. Governor, 255 Md. 445, 258 A. 2d 180 (1969); Washburne v. Hoffman, Etc., 242 Md. 519, 219 A. 2d 826 (1966). We recently observed in Hamilton v. McAuliffe, 277 Md. 336, 353 A. 2d 634 (1976), that the declaratory judgment process is not available to decide purely theoretical questions or questions that may never arise or where a declaration *525would not serve a useful purpose in terminating a controversy.
No live controversy existed between the parties at the time the case was heard or decided by the Circuit Court for Anne Arundel County; the federal and state legislation upon which the estimated revenues depended had been enacted, and no real issue as to the constitutionality of the budget under § 52 (5a) for the fiscal year ending June 80, 1977 was any longer involved. Moreover, the 1977 fiscal year-budget has now expired and as to it no actual controversy can exist. In these circumstances, no useful declaration could be made; indeed, it would be an act of futility, a useless gesture of no effect whatsoever, to consider the appeal. See Md. Tobacco Grow. v. Md. Tob. Auth., 267 Md. 20, 296 A. 2d 578 (1972).
We can, of course, give an opinion in a justiciable declaratory judgment action, even though moot, where extraordinary circumstances exist, such as where there is an urgently needed determination affecting future governmental conduct in which the public concern is both imperative and manifest. See Reyes v. Prince George’s County, 281 Md. 279, 380 A. 2d 12 (1977). That case involved a matter of imperative and manifest public concern where, at the time the case was before us, an actual controversy did exist, and there was an urgent need for a judicial determination of the legality of a governmental bond issue; our decision in that case effectively adjudicated the merits of the litigation. Unlike Reyes, the chronology of the present case indicates that nothing that we could do could undo or remedy that which has already occurred. It is beyond our power to make a decision in this case which will bind any of the parties to it. And while the issue raised in the case is undeniably one of considerable public importance, it may never recur, but if it does, there should be no difficulty in having it passed upon as a live issue. Compare Lloyd v. Supervisors of Elections, 206 Md. 36, 111 A. 2d 379 (1954). Moreover, the views of the Court on the sensitive questions raised in the case are not presently immediately pertinent, *526and no imperative and manifest public need exists for a decision at this time.
Appeal dismissed; appellants to pay costs.
. 61 Op. Att’y Gen. 43 (1976).