ORTH, J., delivered the opinion of the Court.

We decide on this appeal that compensation of employees of a chartered county may not be committed to binding arbitration unless so authorized by a public general law of Maryland or the organic law of that county. We hold specifically that those provisions of the Harford County Code (1965) (the County Code) requiring that such matters with respect to Harford County be submitted to binding arbitration are invalid as not authorized by a public general law or the Harford County Charter (1973) (the County Charter).

I

We are called upon to determine the propriety of an order of the Circuit Court for Harford County denying a petition for a writ of mandamus and for damages which was filed on behalf of all the employees of Harford County who are members of the General Work Force Unit (GWFU) and the Management and Confidential Unit (MCU) by Jack Allen Plott, a member of the GWFU, by Richard Wheeler, a member of MCU, and by the Maryland Classified Employees Association, Inc. (MCEA), which is certified as the exclusive bargaining representative of the employees in the two Units (the appellants). The defendants named in the action were Harford County, Maryland, a body corporate and politic (the County), Charles B. Anderson, Jr., individually and as County Executive, and those persons composing the County Council of Harford County (the Council). A demurrer by Anderson, individually, was sustained without leave to amend and this ruling is not questioned on appeal. The appellees are the County, the County Executive in his official capacity and the County Council.

The suit stemmed from MCEA and the County seeking an agreement under § 201 B of the County Code with respect to compensation of the County employee members of GWFU and MCU. Negotiations began in the fall of 1974. An impasse was reached and the dispute was submitted to arbitration. An arbitration award was issued on 23 May 1975. Under the award, wages were to be increased 7.8% for the next fiscal year (1975-1976), the employees were to receive in-grade step increases on their regular anniversary dates, and the maximum major medical coverage was to be increased from $10,000 to $20,000. Although § 201 B (h)(5) prescribed that the decision of the arbitration board be binding on both parties, the County did not put the award into effect. On 27 May 1975 the County Executive proposed to the Council that all County employees would receive a raise of 7.8% effective 1 July 1975. The Council rejected the proposal. On 29 May the County Executive proposed a $640 across-the-board raise without step increases for all classified employees and exempt secretaries, with certain exceptions, who would not have received that amount under those proposals. This increase was included in the annual budget and appropriation ordinance and was adopted by the County Council on 31 May. No other action was taken by the County to implement the award of the arbitrator. Appellants instituted the action on 14 July 1975. Upon the denial of the petition by the trial court on 18 October 1976, MCEA, Plott and Wheeler noted an appeal to the Court of Special Appeals. We issued a writ of certiorari before decision by that court.

We affirm the judgment of the Circuit Court for Harford County. In so doing, we first affirm an interlocutory order of the trial court denying a motion made by appellants to prohibit appellees from interposing the defense that § 201 B was invalid.

II

The threshold question posed by the interlocutory order, see Maryland Rule 887, denying the motion to prohibit is whether a charter county may attack the validity of its own legislative acts. Precisely, the issue is whether, in an action to compel Harford County, a charter county, to abide by the provisions of a law it duly enacted, it may interpose the defense that the law was invalid?

Appellants would have us hold that appellees cannot challenge the validity of § 201 B. In oral argument before us, however, appellants frankly admitted that they did not know the answer to the question, remarking that they were not aware of any "real law on that in Maryland." They did not refer to any case directly on point in other jurisdictions. They suggested that inasmuch as it was the two bodies in Harford County, namely the County Council and the County Executive, which "put this law on the books and made it valid," they were "therefore bound, in and of themselves, to the constitutionality [and validity] of the law." This was in accord with the comment in appellants' brief that it was "remarkable and contradictory" that appellees have challenged the constitutionality and validity of § 201 B, the very law which the Council passed and the County Executive approved and signed into law. Appellants point to the unsuccessful efforts to repeal the provisions under which arbitration is binding. "Therefore," appellants conclude, "the County Executive and the County Council having enacted § 201 B, having had opportunities to repeal and to amend § 201 B, cannot now challenge its constitutionality and its validity." Appellees characterize this "line of reasoning as totally circular." They say: "Appellants have done no more than assume the merits of their position with respect to Appellees' authority to enact such legislation and conclude that since Appellees possess the authority, they cannot argue that they did not possess it."

It is correct that on the threshold question we write on a clean slate as far as Maryland is concerned. Our recent opinion in Harford County v. Schultz, 280 Md. 77, 86, 371 A.2d 428 (1977) in which we found no justiciable issue in a declaratory judgment action, is not apposite. Baltimore County v. Churchill, Ltd., 271 Md. 1, 313 A.2d 829, app. dism., 417 U.S. 902 (1974) and City of Baltimore v. Concord, 257 Md. 132, 262 A.2d 755 (1970), which appellants cited in their brief for the proposition that "Maryland practice has long provided that political subdivisions lack capacity to question the validity of state law," are not controlling even by analogy, for here, as the trial court noted, "it is the creator, and not a subordinate, which is questioning its own power."

Appellees refer to six cases of this Court which they say clearly support their position that they may challenge the validity of the law. None of them, however, as the trial court recognized, is dispositive of the question, simply not addressing it in the context in which it is before us. Nor are we led to appellees' position by the cases in other jurisdictions cited by them. As appellees indicate, in those cases public employers defended suits in which employee organizations sought to compel compliance with impasse-resolving arbitration provisions by contending that the particular laws were invalid. In none of the cases, however, was the issue of the right of the enacting authority to attack the law it enacted presented or discussed, so the question before us was never reached.

On the other hand, we are not persuaded by the cases in other jurisdictions which appellants cite in support of their claim that appellees cannot mount an attack on the validity of § 201 B.

There are a number of cases throughout the country in which governmental entities or their officers have challenged the validity of their own enactments. In many of them, however, the threshold question is simply not raised; the courts have proceeded directly to the merits of the issue without regard to the propriety of the challenge. Even when the threshold question is considered, no persuasive pattern of decision emerges to dictate its determination. In sum, it seems that, in actuality, the point is left to the discretion of the court. The various courts have considered a number of interests in determining how to exercise that discretion. Under the ordinance here, when the arbitration decision is duly reached, it is binding. Thereafter, the county officials have no discretion with regard to implementing the decision, and their duties in connection with it may be fairly characterized as ministerial. Many states have recognized the principle that a public officer may not attack the constitutionality of a statute in a mandamus proceeding brought to compel the officer to perform a ministerial duty imposed by that statute when his interest is official and not personal. This principle, in keeping with the generally accepted axiom that a litigant can question the constitutionality of a statute only when it is applied to his disadvantage, is based largely upon governmental policy. "It rests upon the theory that the court should accept as final the acts of the Legislature and discourage attacks upon them except where necessary to protect the private interests of the individual asserting invalidity and peculiarly and particularly affected thereby." State v. Steele County, 181 Minn. 427, 430, 232 N.W. 737 (1930). The cases recognizing this principle, however, are not precisely analogous to the case at hand because they do not involve officials directly engaged in the law-making process.

The Superior Court of New Jersey took the flat position that "[a] municipality itself cannot question the validity of its own ordinance. If it becomes discontent therewith, the remedy lies in repeal or amendment. . . ." Springfield Tp. v. Bensley, 19 N.J.S. 147, 164, 88 A.2d 271, 279 (1952). On the other hand, a few courts have permitted an official to interpose the unconstitutionality of a statute as a defense on the theory that an unconstitutional act is a nullity. The defense has also been allowed on the ground that the oath of a public officer to obey the constitution obligates him to make a determination of the statute's constitutionality before obeying it, but other courts have rejected this ground as without merit. Further, 6 McQuillin Mun. Corp. § 20.24 (3rd ed. 1969) states:

"The invalidity of an ordinance may be raised by any interested party to litigation where it is asserted that lawful action is dependent on or derived from the organic law. [Mandamus] is available in a proper case to compel public officers to enforce a municipal ordinance, and in such a proceeding the validity of the ordinance may be in issue."

It relies on Kendall v. Malcolm, 98 Ariz. 329, 334, 404 P.2d 414 (1965) in which a municipality challenged the validity of its own ordinance, citing a violation of the municipal charter. 5 McQuillin Mun. Corp. § 19.04 (3rd ed. 1969) asserts, however, that "only one who is prejudiced by an ordinance may raise the question [of its constitutionality]." We see no distinction between the "validity" and the "constitutionality" of an ordinance in this context, noting that 5 McQuillin Mun. Corp. § 15.19 (3rd ed. 1969) declares that it is firmly established that "[t]he charter of the city is the organic law of the corporation, being to it what the constitution is to the state, and the charter bears the same general relation to the ordinances of the city that the constitution of the state bears to the statutes." Certainly, the charter of a county is in the same position as the charter of a city in this regard.

Many of the states which recognize the general principle that a public officer may not attack the constitutionality of a statute imposing ministerial duties in a proceeding brought to compel performance of those duties have on occasion generated exceptions which forestall the operation of the principle. Although these exceptions are seldom well presented and are often inconsistent with the reasoning underlying the general principle, we find them to be significant because they suggest that the principle is not so much compelling in itself as serving to provide a basis on which a court may decline to decide a constitutional issue, prevent disruption of bureaucratic functions, and enhance judicial economy. Important as these matters are, they may be outweighed by a matter of general public interest, which we believe to be one of the more important exceptions invoked. See Lamm v. Barber, Colo., 565 P.2d 538 (1977); Associated Hospital Service of Maine v. Mahoney, 161 Me. 391, 213 A.2d 712 (1965); Loew v. Hagerle Bros., 226 Minn. 485, 33 N.W.2d 598 (1948); State v. Tyler, 64 Mont. 124, 208 P. 1081 (1922); 30 A.L.R. 378, 387 (1924); 129 A.L.R. 941, 946 (1940).

Ordinarily, we would be loathe to exercise our discretion so as to allow a County to challenge the validity of its own ordinances with respect to ministerial duties. But in the particular circumstances here, where the duties involved, ordinarily discretionary, are ministerial because of the binding arbitration provision, we are inclined to permit the challenge. It is manifest that the validity of a binding arbitration provision of a collective bargaining law which concerns compensation of public employees is a matter of substantial public importance. Absent public general law in the field, it is likely to be a question which will frequently arise in the relationship between public employee and government employer. The implementation of such a binding arbitration award may require an increase in taxes or give rise to fiscal and budgetary problems affecting third parties. Moreover, it appears that the structure of bureaucratic authority will not be seriously disrupted in this instance by permitting the challenge. These considerations, we believe, outweigh contrary interests. In sum, we think the time is ripe and this case appropriate to determine whether a binding arbitration provision with respect to the compensation of public employees is valid, and we shall proceed to make such determination. Compare, Mayor and City Council of Baltimore et al. v. American Federation of State, County and Municipal Employees, AFL-CIO, Council No. 67 and Local No. 44 et al., 281 Md. 463, 379 A.2d 1031 (1977). Therefore, we hold that the trial court did not err in denying appellants' motion to prohibit.

III

Having decided that the trial court did not err in permitting appellees to raise the defense that § 201 B of the County Code was invalid, we turn to the merits of that defense.

In enacting § 201 B the County Council declared the public policy of the County to be "that County employees be permitted to participate effectively in the determination of the terms and conditions of their employment." The purposes of the policy were "to promote harmonious and cooperative relationships between the County and its employees and to protect the public by assuring at all times the orderly and uninterrupted operations of the County Government" and "to strengthen existing relationships between the County, its employees and their representatives by imposing on each the obligation to enter into negotiations with affirmative willingness to reach agreement in matters of wages, hours, working conditions, and other terms of employment with due regard for, and subject to, the provisions of applicable laws and the charter provisions governing public employment and fiscal procedures in Harford County." § 201 B (a).

We center on the provisions of subsection (h) of § 201 B which deals with "Impasse Procedures." Paragraph (1) calls for mediation after a reasonable period of negotiation upon mutual agreement that an impasse has been reached as to a dispute over the terms of an agreement. If the impasse is not resolved at least 130 days after it has been declared, a factfinder shall be selected, ¶ (2), who shall meet with the parties and make written findings of fact and recommendations for the resolution of the dispute no later than thirty days before the budget submission date, ¶ (3). Standards for the factfinder are spelled out in ¶ (4). Paragraph (5) provides the final step in the resolution of disputes:

"In the event that a dispute remains unresolved after thirty (30) days of mediation, the County Executive shall submit the dispute to binding arbitration. The binding arbitration shall be submitted to the American Arbitration Association. The County Executive may also submit a copy of the findings of fact and recommendations of the factfinder along with his own recommendations for settling the dispute. The decision of the arbitration board shall be binding on both parties. (Emphasis added).

The propriety of the order of the trial court dismissing appellants' petition depends upon whether the provisions of ¶ (5) are valid.

Although local governments are normally bound by their contracts, see American Structures v. City of Balto., 278 Md. 356, 364 A.2d 55 (1976), it has long been recognized that questions of invalidity and enforceability arise when governmental bodies attempt by ordinance or contract to surrender or bargain away their discretionary legislative functions.

The validity of collective bargaining agreements in which municipalities bind themselves to exercise their discretionary legislative powers over compensation of public employees in a particular manner, or agree to delegate such powers to binding arbitration, has been the subject of much recent litigation. Where municipal governments have been authorized by higher law, i.e., state constitutional provisions or public general laws or municipal charter provisions, to enter into collective bargaining agreements which bind them in the exercise of their legislative discretion, the courts have generally upheld such collective bargaining agreements, rejecting contentions that they amount to invalid abdications or delegations of legislative authority. On the other hand, in the situation where neither a public general law nor municipal charter provision authorized the municipality to bind itself in the exercise of legislative discretion over public employee compensation, the courts have generally taken the position that attempts to do so in collective bargaining agreements or municipal ordinances are invalid. More than thirty years ago our predecessors gave clear indication of fundamental accord with this position. In Mugford v. City of Baltimore, 185 Md. 266, 44 A.2d 745, decided 28 November 1945 (the decretal order was modified on denial of rehearing on 8 January 1946), "the sole and only question for decision . . . [was] the right of [Baltimore] City to permit members of the [Municipal Chauffeurs, Helpers and Garage Employees Local Union No. 825] to have dues deducted from their wages if they individually so request." Id. at 271. The Court stated that this was a matter of policy and held that "the City may, consistently with its general policy extend to individual employees the privilege of having dues deducted and paid to this or any other Unions, upon request of the individual employee." Id. at 272. The Court observed:

"It could not be imposed without the City's consent, but we think it is within the power of the City to extend the privilege to members of a union, provided it is open to all alike and the request for the deduction comes in the first instance from the individual employee. On the other hand, if the City should undertake to make a deduction at the instance or demand of a union, even though the deduction was terminable by any employee at any time, the arrangement would be open to objection as a delegation of governmental power. . . ." Id. at 272.

In reaching its conclusion, the Court said:

"[T]he Department of Public Works could not bind the City, by contract, in any particular relative to hours, wages or working conditions, either as to union employees, or as to all employees in the same classification. To the extent that these matters are covered by the provisions of the City Charter, creating a budgetary system and a civil service, those provisions of law are controlling. To the extent that they are left to the discretion of any City department or agency, the City authorities cannot delegate or abdicate their continuing discretion. Any exercise of such discretion by the establishment of hours, wages or working conditions is at all times subject to change or revocation in the exercise of the same discretion.

* * *

"The City has no right under the law to delegate its governing power to any agency. The power of the City is prescribed in its charter, and the City Charter constitutes the measure of power that is possessed by any of its officials. To delegate such power to an independent agency would be a serious violation of the law. To recognize such delegation of power in any City department might lead to the delegation of such power in all departments, and would result in the City government being administered regardless of its charter." Id. at 270-271.

This Court has not thereafter expressed a contrary view.

The County ordinance in question plainly attempted to bind the County in the exercise of legislative discretion over compensation of its public employees. Harford County, pursuant to the Constitution of Maryland, Article XI A, adopted a charter as its instrument of government in order to obtain the benefits of self-government and home rule. Under its Charter, the powers of the County, a body corporate and politic, § 101, "shall be exercised only by the County Council, the County Executive and other officers, agents and employees of the County acting under their respective authorities." § 102. "The Legislative Branch of the County government shall consist of the County Council . . . and the officers and employees thereof." § 201. "All legislative powers which may be exercised by Harford County under the Constitution and laws of Maryland, including all law making powers heretobefore exercised by the General Assembly of Maryland but transferred to the people of the County by virtue of the adoption of this Charter, shall be vested in the Council." § 202. "In all of its functions and deliberations, the Council shall act as a body, and shall have no power to create standing committees or to delegate any of its functions or duties to a smaller number of its members than the whole." § 203.

The County Budget, consisting of the current expense budget, the capital budget and the capital program, and the budget message, "shall represent a complete financial plan for the County reflecting all receipts and disbursements from all sources, including all revenues, all expenditures, and the surplus or deficit in the general fund and all special funds of the County government." § 503. There are provisions for the submission of the budget by the County Executive to the County Council, § 509, and for public hearings, § 511. Thereafter, the Council may decrease or delete any items in the budget except those required by law, and except any provisions for debt service or obligations then outstanding or for estimated cash deficits. § 512 (a). The budget shall be adopted by the Council or stand adopted upon failure of the Council to adopt it, as provided by § 512 (b) and (c). No expenditures of County funds shall be made or authorized in excess of the available unencumbered appropriations therefor. § 520. Although the County may incur debt, no indebtedness for a term of more than one year shall be incurred by the County to meet current operating expenses. § 524. Salaries and wages of classified and exempt service employees, see § 602, shall be determined in accordance with established classification and salary plans, and to be effective they must be submitted to the Council for legislative action thereon. § 603. The personnel law of the County shall include a position classification plan and pay plans. § 604.

We assume, but have no need to decide, that, in light of the above cited cases on the point, had a State public general law or the County Charter authorized the binding arbitration provisions enacted by the County Council, the provisions would be valid. But there is no such authority in either a public general law or the County Charter. As is evident from the cases above cited, the prevailing rule in other jurisdictions is in complete accord with the view expressed in Mugford to the effect that absent such authorization it is invalid for a municipality or charter county to attempt to bind itself in the exercise of legislative discretion over compensation of its public employees. We follow that rule. Because the Harford County ordinance attempted to bind the County in the exercise of its legislative discretion over public employee compensation without being authorized to do so by a public general law or by the County Charter, the provisions of the ordinance to that end are invalid. We hold that the trial court did not err in denying appellants' petition for a writ of mandamus.

Judgment affirmed; costs to be paid by appellants.