Three uniformed civilian guards, who were denied appointment to the Federal Protective Service (FPS), brought this suit against the United States and against the regional directors of the General Services Administration (GSA) and the Civil Service *673Commission for the Chicago area. In the complaint and on appeal, the plaintiffs pursued two separate courses. They challenged, in Count I of the complaint, the legality of the FPS. In Count II, they alleged that the government’s refusal to reclassify them as Federal Protective Officers was an abuse of discretion. The district court dismissed the complaint for lack of subject matter jurisdiction and failure to state a claim on which relief can be granted. We affirm the district court’s dismissal of Count I; we also affirm the dismissal of Count II but on the alternative ground that the plaintiffs have not exhausted available administrative remedies.
I.
According to the complaint, the GSA employed for many years uniformed civilian guards as special police to protect federal buildings under its control. When these buildings became a target of terrorist activity, the GSA thought it necessary to employ federal officers capable of doing more hazardous protective work than was expected of the uniformed guards. In 1971, the GSA created the Federal Protective Service to meet this need. FPS officers were required to pass a training course in various aspects of police work, including the use of firearms and the detection of bombs, and were held to rigorous physical fitness standards. In turn, the officers were classified by the Civil Service Commission in the “police position” series and, as a result, they received higher GS grades than do uniformed guards. In addition, geographical pay adjustments are allocated from time to time to members of the police series.
The GSA continues to appoint uniformed guards to the FPS, but now it also recruits from outside sources. Moreover, the guards, like new applicants, must first pass an examination conducted by the Civil Service Commission which includes the training course in police work and a physical examination. The plaintiffs applied for.appointment to the FPS in 1974. Although they successfully completed a month-long training course, both Mr. Martynowski and Mr. Swiatly failed the physical examination. According to the allegations in their complaint, they suffered from “diabetes, ulcers, overweight problems and various anatomical deformities”. Mr. Jarecki refused to take the physical examination insisting that as a veteran, a status shared by the other plaintiffs, he is exempt from this requirement.
In their complaint, the plaintiffs asked the district court to grant two basically inconsistent forms of relief: either to order the GSA to abandon the FPS and revert to its pre-1971 practice of appointing only uniformed guards to act as special police or, instead, to order the GSA and Civil Service Commission to reclassify the uniformed guards as FPS officers. They also requested back pay, reflecting the difference between the salaries of guards and that of FPS officers, computed from the time the plaintiffs passed the training course.
II.
We address first the plaintiffs’ request for an order that would compel the GSA to draw all special police from the ranks of the uniformed guards. The plaintiffs contend that jurisdiction to grant this relief is conferred by the mandamus statute, 28 U.S.C. § 1361, which permits a federal court to compel an officer of the United States “to perform a duty owed to the plaintiff”.1 According to the plaintiffs, a statutory duty to appoint only uniformed guards is imposed upon the GSA by the Protection of Public Property Act, 40 U.S.C. § 318, which provides in part that:
“The [General Services] Administrator . may appoint uniformed guards of said administration as special policemen without additional compensation for duty in connection with the policing of public buildings . . . Such special policemen shall have the same powers as sheriffs.”
*674Mandamus is a powerful and unusual remedy that issues only in carefully circumscribed situations. It is traditionally available to compel a ministerial duty owed by the agency and then only when the statute defining that duty is “clear and free from doubt”. Smith v. Grimm, 9th Cir. 1976, 534 F.2d 1346, 1352; McClendon v. Blount, 7th Cir. 1971, 452 F.2d 381, 383; Hammond v. Hull, 1942, 76 U.S.App.D.C. 301, 303, 131 F.2d 23, 25, cert. denied, 1943, 318 U.S. 777, 63 S.Ct. 830, 87 L.Ed. 1145. The language of the Protection of Property Act, however, is not mandatory. The statute does not, on its face, compel the appointment of uniformed guards as special police; it states that the GSA “may” appoint the guards at no additional compensation. Were we to adhere strictly to the traditional view of mandamus, our discussion would end with that observation.
The plaintiffs ask us, however, to consider the legislative history of Section 318 in determining whether there is a duty imposed by Section 318 that is subject to mandamus. Some courts have held that the need to construe a statute does not deprive the court of jurisdiction under Section 1361, acknowledging that a duty often becomes ministerial “only after a court has reached its own judgment about a disputed legal question and its application to a factual situation.” Seaton v. Texas Co., 1958, 103 U.S.App.D.C. 163, 168, 256 F.2d 718, 723, quoted in Haneke v. Secretary of Health, Ed. & Welfare, 1976, 175 U.S.App.D.C. 329, 334, 535 F.2d 1291, 1296 n.16. Commentators, too, urge that we break away from the “clear and free from doubt” standard, and recognize that mandamus cases, like other suits for specific relief, present the question whether the administrative action complained of falls outside the scope of authority delegated to the executive department and is, therefore, subject to judicial control.2 We shall look to the legislative history of Section 318, therefore, to see what light it throws on the question.
Before the enactment of Section 318, the Commissioner of Public Buildings was granted statutory authority to appoint federal employees as special policemen in the District of Columbia, 43 Stat. 175 (May 27, 1924) and outside the District during the period of national emergency. 56 Stat. 1000 (October 26, 1942). Formerly, the government had relied on state police to perform all necessary protective work in the area outside the District. It became apparent, however, that state police would often be unavailable or without jurisdiction to act on newly acquired federal property. Section 318, therefore, removed all limitations on the Commissioner’s power to use federal officers. It also made clear that federal officers performing special protective duties were authorized to make arrests and must be recognized by courts as arresting officers. 1948 U.S.Cong. Service 1627.
The history amply supports the GSA’s position that it has the power to establish the FPS. Whether the GSA exercises its authority by appointing employees to special police duties from time to time or by creating a permanent position for federal officers who act only as special police is immaterial.
*675The more serious contention of the plaintiffs is that Congress deprived the GSA of all elements of choice in selecting the personnel of the FPS when it enacted Section 318. The version of the bill presented to the House of Representatives contained no references to uniformed guards and, indeed, the 1942 statute on which Section 318 was modeled granted authority to appoint federal “employees”. The bill was amended in the Senate, however, “so as to make clear that only uniformed guards are to be appointed as special policemen, since they are the ones who are carefully selected and trained for police service”. Senate Report No. 1176.
It may well be that Congress specifically authorized the GSA to draw only upon the uniformed guards to serve as police officers. But the limitation to guards was, at most, intended as a means of ensuring capable personnel. The congressional purpose behind Section 318 would be subverted by requiring the GSA, at this stage, to respect the technical limitation to guards at the price of not employing qualified officers for police work.3 We hold, therefore, that the GSA did not depart from its delegated authority when it chose to bypass the limitation to guards in favor of discharging its principal statutory duty to appoint carefully trained federal officers for the protection of federal buildings.
Our reading of the legislative history of Section 318 leads us to the conclusion that the plaintiffs also lack standing to seek an order against the GSA. A primary factor in deciding whether the requirement of standing is met is whether “the interest sought to be protected by the complainant is arguably within the zone of interests to be protected or regulated by the statute in question”. Data Processing Service v. Camp, 1970, 397 U.S. 150, 153, 90 S.Ct. 827, 830, 25 L.Ed.2d 184. This aspect of the requirements of standing is succinctly incorporated into the mandamus statute. Section 1361 states that mandamus is proper to compel a duty “running directly to the plaintiff”. In our view, Section 318 was designed to enable the GSA to discharge its duty to the public and to the government to protect federal property; the reference in the statute to the uniformed guards is merely an incident of this design. Since the statute does not impose a duty on the GSA for the benefit of the guards, we also conclude that the plaintiffs have failed to satisfy this prerequisite for mandamus relief.
Finally, we note that even if the plaintiffs had succeeded in showing that the GSA acted beyond the scope of its statutory power when it recruited special police from outside the ranks of the guards, we would not grant the relief sought here. This Circuit recently considered the occasions when the doctrine of sovereign immunity may prevent a court from granting an affirmative remedy. Schlafly v. Volpe, 7th Cir. 1974, 495 F.2d 273. Even when a suit falls within a recognized exception to that doctrine,4 we cannot grant relief that would place “ ‘an intolerable burden on governmental functions, outweighing any consideration of private harm’ ”. 495 F.2d at 280. This is an appropriate consideration here, whether or not the doctrine of sovereign immunity has independent application in Section 1361 cases,5 because of the tradi*676tional principle that extraordinary relief will not be granted when it causes undue hardship to the defendant or to the public. In our view, the probability that the public would be harmed as a result of an order compelling the GSA to rely , solely on the uniformed guards to perform all special protective duties justifies dismissal of this portion of the plaintiffs’ complaint.6
III.
We turn now to the plaintiffs’ request for reclassification as FPS officers. In Count II of the complaint the plaintiffs state that the refusal of the GSA and Civil Service Commission to appoint them to the higher grade position was wrongful for two reasons. First, the plaintiffs insist that the physical examination imposed on the guards was an improper barrier to their promotion because rigorous physical fitness standards are not necessary for the effective performance of the duties of an FPS officer. The plaintiffs allege, for example, that the GSA has hired FPS officers in regions other than Chicago who suffer from disabilities similar to those that disqualified the plaintiffs. Second, the guards maintain that it is improper to deny them the benefits that attach to the position of FPS officer when they already perform the duties of that position.
In support of their right to an order promoting them to the higher Grade Schedule position, the plaintiffs argue that the Examination and Selection Act, 5 U.S.C. § 3363, imposes a duty on the GSA and Civil Service Commission to waive the physical requirements for veterans requesting promotions to another position, “if, in the opinion of the Commission or other examining agency, . . . the preference eligible is physically able to perform efficiently the duties of the position”.7 Because the stated purpose of the Classification Act, 5 U.S.C. § 5101, is to provide a system whereby employees are classified in accordance with the principle of “equal pay for substantially *677equal work”,8 the plaintiffs also maintain that the Civil Service Commission has a statutory duty to reclassify guards who perform the work of FPS officers. The plaintiffs claim a right to retroactive monetary relief for the period of misclassification, as well, based primarily on the Back Pay Act, 5 U.S.C. § 5596(b).9 The district court dismissed, taking the view that the uniformed guards did not allege any infringement of their statutory rights because they continued to receive the pay for which they agreed to work.
We cavil not at the district court’s dismissal of the plaintiffs’ claim for relief had that claim rested solely on the theory that the GSA and the Civil Service Commission acted arbitrarily when they originally imposed strict physical prerequisites for the job of FPS officer in the Chicago region. We know of no statute that limits an agency’s power to impose requirements that it believes are necessary for a particular position. Ordinarily, these decisions are not amenable to judicial control by way of mandamus or otherwise because courts are not qualified to substitute their judgment on these issues for that of an agency. Nor is the plaintiffs’ bare allegation that the physical requirements were adopted at a late date in an attempt to phase out the guard force sufficient to state a claim of discriminatory treatment that would entitle them to judicial review.
A very different situation is presented when the plaintiffs also allege that, despite their physical disabilities, they currently perform the duties of the position to which they have been denied promotion. The allegations in the complaint do not merely challenge the original decision to impose stringent physical qualifications on the job of FPS officer, nor do they challenge the initial decision to classify the uniformed guards and FPS officers at two different grades. Indeed, the plaintiffs concede that the official descriptions of the two jobs differ substantially. Rather, the thrust of the plaintiffs’ argument here is that, as a factual matter, FPS officers are not given more hazardous tasks and, therefore, there are at present no differences between the two positions. Accepting these allegations as true, we agree that they state a good claim for prospective promotion.
The Supreme Court recently observed that there is “a difference between prospective reclassification, on the one hand, and retroactive reclassification resulting in money damages, on the other.” United States v. Testan, 1976, 424 U.S. 392, 403, 96 S.Ct. 948, 955, 47 L.Ed.2d 114, 124. The plaintiffs in that case had alleged that the duties they performed were identical with those performed by other trial attorneys who were classified at a higher GS rating. They sued in the Court of Claims for an order directing reclassification and awarding back pay.10 In reversing the Court of Claims decision, the Supreme Court referred to the traditional rule, relied on by the district court'in this case, that a federal employee “is entitled to receive only the salary of the position to which he was appointed, even though he may have performed the duties of another position or claims that he should have been placed in a higher grade”. 424 U.S. at 406, 96 S.Ct. at 957, 47 L.Ed.2d at 126. Although the Court held that neither the Back Pay Act nor the Classification Act changed this rule by creating a substantive right to back pay for the period of misclassification, in a signifi*678cant dictum concerning the scope of the plaintiffs’ statutory right to equal pay for equal work under the Classification Act, the Court suggested that a “possible avenue of relief — and it, too, seemingly, is only prospective — is by way of mandamus, under 28 U.S. § 1361, in a proper federal district court”. 424 U.S. at 403, 96 S.Ct. at 956, 47 L.Ed.2d at 124.
In light of the holding in Testan, we do not doubt that the district court properly denied the plaintiffs’ request for back pay.11 But we also read that decision as support for the plaintiffs’ contention that the Classification Act grants them a substantive right to be reclassified to the position in the General Schedule scale occupied by the FPS officers, if it is true that both groups of employees now perform the same work.
The Testan Court, of course, did not expressly decide that the Classification Act requires the Civil Service Commission to compare the duties performed by the plaintiffs with those performed by other employees who are classified differently. That conclusion was implicit, however, in the Court’s suggestion that the plaintiffs in Testan, who also complained that their classification did not square with that of other employees performing the same duties, could request prospective relief from the Civil Service Commission or a district court. And other courts have held that without such comparison, the statutory mandate of “equal pay for equal work” is “nothing more than a slogan”. Haneke v. Secretary of Health, Ed. & Welfare, 1976, 175 U.S.App.D.C. 329, 535 F.2d 1291, 1298; Testan v. United States, 1974, 499 F.2d 690, 691, 205 Ct.Cl. 330, 332, rev’d on other grounds, 424 U.S. 392, 96 S.Ct. 948, 47 L.Ed.2d 114. We agree. The uniformed guards will hardly be consoled by the district court’s observation in this case that they were classified properly at one time and continue to receive the pay appropriate to that classification, when they can identify others who receive more money for the same duties. Nor will it console the guards to learn that FPS officers receive more pay because the latter have passed a physical examination, when the guards are called upon to perform *679identical work despite having failed the physical.12
Moreover Congress has provided these plaintiffs with a substantive right to prospective promotion in the Veterans Preference Act. Congress chose to encourage and reward military service by granting certain preferences to veterajis who desire public employment. In 5 U.S.C. § 3363, Congress expressed its will that veterans not be denied promotions on the basis of physical requirements unless these requirements are necessary for the effective performance of the position that the veteran seeks. When a veteran alleges that he already performs the duties of the new position, we think he has placed himself clearly within the intended ambit of this legislative preference. We conclude, therefore, that the district court should not have dismissed this portion of the plaintiffs’ complaint for failure to state a claim for relief.
IV.
This suit is premature. None of the plaintiffs exhausted the extensive remedies provided by the Classification Act,13 see 5 U.S.C. § 5512; 5 C.F.R. §§ 511:601 et seq., although the Civil Service Commission is more capable than the district court of resolving the question in this suit. Indeed, the Commission may eliminate the need for judicial review by identifying those duties in the police position series which qualify the FPS, but not the uniformed guards, for that classification. We caution the plaintiffs, moreover, that our review of the Commission’s conclusions concerning the duties actually performed by both groups of employees is necessarily limited and is based on the agency record. See Haneke v. Secretary of Health, Ed. & Welfare, 1976, 175 U.S.App.D.C. 329, 335, 535 F.2d 1291, 1297. We hold, therefore, that those portions of the plaintiffs’ complaint that state a claim for relief must be dismissed for failure to exhaust administrative remedies.
The district court’s dismissal of the plaintiffs’ complaint is, therefore, Affirmed.