OPINION OF THE COURT
SEITZ, Circuit Judge.
Ronald Castille, the District Attorney of Philadelphia County, appeals the orders of the district court denying his motion to intervene as of right, 113 F.R.D. 615, and approving the settlement agreement reached by the parties in this prison conditions litigation, 654 F.Supp. 1042. This court has appellate jurisdiction pursuant to 28 U.S.C. § 1291 (1982).
I.
In 1982 ten inmates at the Holmesburg Prison in Philadelphia filed a pro se complaint in federal district court seeking damages and injunctive relief for themselves and for a class consisting of all inmates of the Holmesburg prison since that date and all future Holmesburg inmates. Counsel appointed for the plaintiffs filed an amended complaint, pursuant to 42 U.S.C. § 1983 (1982), alleging that the conditions of the prison violated the eighth and fourteenth amendments. The amended complaint named as defendants the City of Philadelphia, the Philadelphia officials responsible for supervising the prisons, the Board of Trustees of the Philadelphia Prison System, the Warden of the Holmesburg Prison [594]*594(collectively, the City Defendants or the City), and several state officials.
The district court dismissed the action on res judicata and abstention grounds in light of state court litigation, Jackson v. Hendrick, challenging the constitutionality of the Philadelphia prisons. This court reversed the district court’s conclusion that the Jackson v. Hendrick litigation precluded hearing this action. Harris v. Pernsley, 755 F.2d 338 (3d Cir.1985). We denied the City’s petition for rehearing on March 21, 1985. 758 F,2d 83 (3d Cir.1985). On November 4, 1985, the Supreme Court denied the defendants’ petition for certiorari. — U.S. -, 106 S.Ct. 331, 88 L.Ed.2d 314 (1985).
After remand to the district court, the plaintiffs filed a second amended complaint expanding the plaintiff class to include the inmates of all the Philadelphia prisons and adding the wardens of the Detention Center and the House of Corrections as party defendants. The plaintiffs and City defendants then entered into settlement negotiations. On August 8,1986, they informed the court that they had reached agreement. On this same date, the Mayor wrote the District Attorney a letter informing him that the parties had reached an agreement in this litigation and in the pending state court action.1 A copy of a proposed consent decree was submitted to the district court on August 15.
On August 19 the District Attorney filed a motion to intervene as of right, pursuant to Fed.R.Civ.P. 24(a), as a full party defendant, or in the alternative, to intervene permissibly under Fed.R.Civ.P. 24(b). Both the City Defendants and the plaintiffs opposed this motion.
The parties then withdrew the proposed consent decree. After consulting with representatives of the District Attorney and the state courts, the City defendants renegotiated a settlement agreement with the plaintiffs. On October 3, the parties, except the state court defendants, submitted a second proposed consent decree to the court. It contained, among other things, a limit on the prison population.
After the second proposed consent decree was delivered to the district court, the District Attorney filed a proposed answer to the plaintiffs’ complaint denying that the conditions in the Philadelphia prisons were unconstitutional. In addition, he submitted a proposed cross-claim against the City Defendants, alleging that the proposed consent decree unlawfully interfered with his functions. The cross-claim sought a declaratory judgment that the City had no power to interfere with the District Attorney’s duties, including entering an agreement that would result in the release of inmates who are serving sentences or who present either a threat to the community or a risk that they will fail to appear for trial. The District Attorney also sought a permanent injunction against the City to prevent it from entering any settlement that interfered with his duties.
The district court held two evidentiary hearings and heard oral argument on the District Attorney’s motion to intervene. The District Attorney presented witnesses and introduced stipulated statements of a number of persons. Appellees did not present any evidence, but did cross-examine the District Attorney’s witnesses.
Edward Rendell, the District Attorney from January 1978 to January 1986, testified that he had no knowledge of this litigation while he served as the District Attorney. He further testified that he believed that a cap on prison populations would affect the District Attorney’s interest in prosecutions because those released with[595]*595out posting bail would not appear for their trials.
The present District Attorney testified that he did not learn of this litigation until August 1986. Deputy District Attorney Eric Henson testified that he became aware of this litigation in March 1985, when he read this court’s opinion,.and that he did not bring the case to the attention of the then District Attorney. He further stated that at that time he believed the City defendants were adequately representing the District Attorney’s interest and that should the City decide not to litigate the case, it would inform the District Attorney before taking any action.
The District Attorney presented the testimony of Maria Terpolilli, the Senior Supervisor of the Bail Hearings Unit of the Pretrial Services Division of the Philadelphia Court of Common Pleas, to provide evidence of the failure to appear rates for persons under various release programs, including the one instituted by the Jackson v. Hendrick litigation, and of the rearrest rates for persons released under the Jackson v. Hendrick program.2 The District Attorney attempted to show that the failure to appear and rearrest rates under the Jackson v. Hendrick program were extremely high. After cross-examination of Terpolilli, however, the district court refused to admit the ratios that Terpolilli derived from her statistics, finding the ratios “meaningless.”
In addition, the District Attorney proffered statements from a number of state court officials as to their discussions with City officials about the proposed agreements. Finally, the parties stipulated to statements from prison officials concerning the improvements in prison conditions since the Jackson v. Hendrick litigation was instituted. After hearing oral argument, the district court took the District Attorney’s motion to intervene under advisement.
At the beginning of the hearing on the proposed consent decree, the district court informed the District Attorney that it was going to deny his motion to intervene. With the consent of the parties, however, the court permitted the District Attorney to present his objections to the proposed consent decree, both at the hearing and in written submissions. At the hearing, the District Attorney argued that the proposed settlement would endanger public safety, that there was no reason to enter such an agreement absent a finding that the conditions in the Philadelphia prisons were unconstitutional, that the consent decree went beyond what is required by the Constitution, and that the settlement would, in effect, undo the bail determinations and sentences of state court judges. The City and the plaintiffs reiterated their contention that the proposed settlement was fair and reasonable.
On December 31, the district court filed its opinion and order formally denying the District Attorney’s motion to intervene, finding that he failed to meet any of the requirements of the rule for intervention of right. In addition, she denied his motion for permissive intervention. Because of these rulings it was not necessary for the district court to address the District Attorney’s proposed answer to the complaint and proposed cross claim. On this same date, the district court entered its order approving the settlement agreement proposed by the plaintiffs and City defendants.3 These appeals by the District Attorney followed.4
II.
The District Attorney asserts that, contrary to the district court’s ruling, he has [596]*596an absolute right to intervene in this action as a full-party defendant to litigate the constitutionality of the conditions of the Philadelphia prison system and the relief, if any, to which the plaintiffs may be entitled. Under Rule 24(a)(2),5 a person is entitled to intervene if (1) the application for intervention is timely; (2) the applicant has a sufficient interest in the litigation; (3) the interest may be affected or impaired, as a practical matter by the disposition of the action; and (4) the interest is not adequately represented by an existing party in the litigation. See Commonwealth of Pennsylvania v. Rizzo, 530 F.2d 501, 504 (3d Cir.), cert denied sub nom. Fire Fighters Union v. Pennsylvania, 426 U.S. 921, 96 S.Ct. 2628, 49 L.Ed.2d 375 (1976). Although these requirements are intertwined, each must be met to intervene as of right. See, e.g., New Orleans Public Service, Inc. v. United Gas Pipe Line Co., 732 F.2d 452, 463 (5th Cir.) (in banc), cert. denied sub nom. Morial v. United Gas Pipe Line Co., 469 U.S. 1019, 105 S.Ct. 434, 83 L.Ed.2d 360 (1984); 3B J. Moore & J. Kennedy, Moore’s Federal Practice U 24.07[1] at 24-50 (2d ed. 1982); 7C C. Wright, A. Miller, & M. Kane, Federal Practice and Procedure: Civil 2d § 1908 at 262 (1986).6
A.
Because of its pervasive importance in the setting of the case, we at once focus on the second requirement: whether the District Attorney has shown a sufficient interest in this litigation. This circuit has not addressed what type of interests are necessary to entitle an applicant to intervene as of right. And as one court has noted, given the multitude of situations in which intervention controversies can arise, what constitutes such an interest “defies a simple definition.” Restor-A-Dent Dental Laboratories, Inc. v. Certified Alloy Products, Inc., 725 F.2d 871, 874 (2d Cir.1984).
The Supreme Court has stated that under Rule 24(a)(2), an applicant’s interest must be one that is “significantly protectable.” Donaldson v. United States, 400 U.S. 517, 531, 91 S.Ct. 534, 542, 27 L.Ed.2d 580 (1970). Several circuits have concluded that an applicant must demonstrate a legal interest in the action to intervene as of right. Southern Christian Leadership Conference v. Kelley, 747 F.2d 777, 779 (D.C.Cir.1984) (the interest must be “legally protectable”); New Orleans Public Service, Inc., supra, 732 F.2d at 463 (intervention as of right requires a “direct, substantial, legally protectable interest in the proceedings”); Wade v. Goldschmidt, 673 F.2d 182, 185 (7th Cir.1982) (same). But see Smith v. Pangilinan, 651 F.2d 1320, 1324 (9th Cir.1980) (an applicant “need not show that he has a legal or equitable interest in jeopardy ... [but] must show that he has a ‘protectable interest’ in the outcome of the litigation of sufficient magnitude to warrant inclusion in the action.”) (citations omitted). In addition, a number of courts have concluded that this interest must be “direct,” as opposed to contingent or remote. See Restor-A-Dent Dental Laboratories, supra, 725 F.2d at 874; Air Lines Stewards and Stewardesses Association, Local 550 v. American Airlines, Inc., 455 F.2d 101, 105 (7th Cir.1972); 3B Moore’s Federal Practice, supra, 1124.07[2] at 24-59.
Courts have not been able to develop more than these general guidelines to answer what type of interest is necessary for intervention. See generally, 3B Moore’s Federal Practice, supra, 1124.07[2] at 24-57 (“The exact nature of the interest required ... has eluded a precise and authoritative judicial definition____”). Because Rule 24(a)(2) was designed to permit courts [597]*597to solve intervention disputes in a pragmatic manner, it “requires consideration of all the competing and relevant interests raised by an application for intervention.” United States v. Hooker Chemicals & Plastics Corp., 749 F.2d 968, 983 (2d Cir.1984); see Neusse v. Camp, 385 F.2d 694, 700 (D.C.Cir.1967).
B.
With these rather conclusory guidelines in mind, we turn now to the District Attorney’s argument that the district court erred in concluding that this litigation did not sufficiently implicate his interests to require intervention under Rule 24(a)(2). We must first determine the scope of review of the district court’s determination denying the District Attorney’s motion for intervention of right.
As we noted above, intervention controversies arise in many different contexts, and require the court to consider the pragmatic consequences of a decision to permit or deny intervention. The variety of situations in which an application may arise counsels against setting strict legal standards by which courts may measure applications under Rule 24(a)(2). See Shreve, Questioning Intervention of Right — Toward A New Methodology Of Decisionmaking, 74 Nw. U.L. Rev. 894, 916-24 (1980). This same reasoning supports an abuse of discretion standard of review, which we now adopt. See United States v. Hooker Chemicals & Plastics Corp., supra, 749 F.2d at 991. But see People of State of California v. Tahoe Regional Planning Agency, 792 F.2d 779, 781 (9th Cir.1986) (district court’s denial of intervention as of right reviewed de novo).
We note, however, that our review of district court’s decisions denying intervention of right is more stringent than the abuse of discretion review accorded to denials of motions for permissive intervention. Rule 24(a)(2) restricts the district court’s discretion by providing that an applicant “shall be permitted to intervene” if he or she satisfies the requirements of the Rule. See Stringfellow v. Concerned Neighbors in Action, — U.S.-, 107 S.Ct. 1177, 1185 n. 1, 94 L.Ed.2d 389 (1987) (Brennan, J., concurring). We, therefore, will reverse a district court’s determination on a motion to intervene of right if the court “has applied an improper legal standard or reached a decision that we are confident is incorrect.” United States v. Hooker Chemicals & Plastics Corp., supra, 749 F.2d at 992; see generally, United States v. Criden, 648 F.2d 814, 817-19 (3d Cir.1981) (discussing the meaning of the “abuse of discretion” standard of review).
In this case, the District Attorney asserts a legal interest in support of his motion to intervene: his duties as a public official. The scope of his interest is defined by the scope of his legal duties under Pennsylvania law.7 See Olden v. Hagerstown Cash Register, Inc., 619 F.2d 271, 273 (3d Cir.1980). If his rights and duties, as defined by Pennsylvania law, may be affected directly by the disposition of this litigation, the District Attorney has a sufficient interest to intervene as of right in this action. See Blake v. Pallan, 554 F.2d 947, 953 (9th Cir.1977); Hines v. D Artois, 531 F.2d 726, 738 (5th Cir.1976); see also Neusse v. Camp, supra, 385 F.2d at 700 (state banking commissioner has right to intervene in action brought by a state bank against the Comptroller where federal law incorporates the state’s banking laws because he has an interest in the enforcement of the state laws’ policies). We turn then to a recitation of the basic terms of the consent decree so that they may be juxtaposed with the authority accorded the District Attorney under Pennsylvania law.
At the time the consent decree was approved, there were 4300 inmates in the Philadelphia prison system; approximately two-thirds of the inmates were awaiting hearing or trial. The decree requires the inmate population in the present facilities to be reduced, in stages, to 3750 persons within six months. The ceiling on the pris[598]*598on population agreed to by the parties is higher than the ones that have been ordered by the Pennsylvania courts in the Jackson v. Hendrick litigation. See, e.g., Jackson v. Hendrick, supra, 503 A.2d at 403; Jackson v. Hendrick, supra, 446 A.2d at 231.
If the inmate population of the prisons exceeds the maximum permissible under the consent .decree, the agreement provides that the City “shall seek the release, through the mechanism of the Bail Master appointed by the Jackson court or otherwise, of persons being held either on the lowest bail or persons sentenced to the Philadelphia prisons with less than sixty days remaining to serve on their sentences.”8 The City will not to seek the release of inmates charged with murder or forcible rape, or persons who, if released, posed an imminent threat to the public or themselves.
The settlement recognizes that the prison population fluctuates daily, and thus provides that the population may exceed the maximum temporarily, but not for more than seven days consecutively or twenty days out of any forty. If the population of a facility exceeds the limit for more than the allowable flux time, the decree provides that the City défendants cannot admit additional inmates to the facility. This provision does not apply to “persons charged with, or convicted of, murder, forcible rape, or a crime involving the use of a gun or knife in the commission of an aggravated assault or robbery.” 9
The statute establishing the office of district attorney provides, in relevant part: “The district attorney shall sign all bills of indictment and conduct in court all criminal and other prosecutions____” 16 Pa.Stat. Ann. § 1402(a) (Purdon Supp.1986). The Pennsylvania Supreme Court has interpreted this statute as giving the District Attorney the power, and the duty, “to represent the Commonwealth’s interests in the enforcement of its criminal laws.” Commonwealth ex rel. Specter v. Bauer, 437 Pa. 37, 41, 261 A.2d 573, 575 (1970). The District Attorney is the “sole public official charged with the legal responsibility of conducting ‘in court all criminal and other prosecutions.’ ” Id. at 43, 261 A.2d at 576 (citation omitted).
In particular, the District Attorney advocates specific bail levels and may appeal bail determinations with which he disagrees. See, e.g., Commonwealth of Pennsylvania v. Truesdale, 449 Pa. 325, 296 A.2d 829 (1972) (District Attorney appealing bail decision). The District Attorney also has the power to advocate sentences, to defend convictions in both state court actions and habeas actions in federal court, and to represent the Commonwealth in challenges to the constitutionality of the state’s penal statutes. See Specter v. Bauer, supra, 437 Pa. at 42-43, 261 A.2d at 575-76. In short, the District Attorney is charged with the responsibility of enforcing the Commonwealth’s criminal statutes.
The Philadelphia Home Rule Charter vests the Philadelphia Department of Public Welfare with the responsibility of supervising the Philadelphia prison, including the power to set the capacity of the institutions. 351 Pa.Admin.Code § 5.5-700(c) (1986).10 The Charter further provides that the Board of Trustees of the Philadelphia Prison System has the responsibility of managing the prisons. 351 Pa.Admin.Code § 5.5-701 (1986).
The Home Rule Charter, however, cannot provide the City with powers contrary to those granted by state statutes. 53 Pa.Stat.Ann. § 13133(b) (Purdon 1957). The Charter, thus, cannot provide support for the City to encroach on any duties vested in the District Attorney by state [599]*599statute. Specter v. Bauer, supra, 437 Pa. at 43, 261 A.2d at 576.
Given the pertinent terms of the consent decree and the legal duties of the District Attorney, we must decide whether the duties enumerated above are implicated sufficiently in this prison overcrowding litigation that the District Attorney has the right to intervene. As we understand the District Attorney’s position, he seeks to intervene in this action to litigate the prisoners’ claims of unconstitutional conditions and to prevent a settlement to which he objects. According to the District Attorney, he has a right to intervene as a full-party defendant because limits on prison populations are a traditional response to a finding of unconstitutional conditions in prisons and this remedy would adversely affect his functions.
The District Attorney asserts that a limitation on the prison population will interfere with his prosecutorial powers in two ways. First, he argues that a prison cap will result in the release of inmates who have not posted the bond set by state court judges or inmates who have not served their full sentences. This, in turn, will result in his work going for naught and will hamper his ability to prosecute cases because those released without posting bond will not appear for their trials.
Second, he directs the court’s attention to the fact the prison cap may make it impossible for the City prisons to admit additional persons. He contends that if the City refused to operate any jails, the refusal would interfere with his duties because his function as a prosecutor would be rendered meaningless. According to the District Attorney, it therefore follows that if some individuals are not admitted to prison because of the ceiling placed on the prison population, his role is rendered meaningless for those individuals.
In considering whether the District Attorney has a sufficient interest in this case, for intervention purposes, we will analyze the District Attorney’s position in two stages: first, whether he has a right to intervene to oppose the plaintiff's claims of unconstitutional conditions on the merits and second, whether he has a right to participate in the formation of the remedy.
Given the nature of an applicant’s interest, he or she may have a sufficient interest to intervene as to certain issues in an action without having an interest in the litigation as a whole.11 See Howard v. McLucas, 782 F.2d 956, 962 (11th Cir.1986) (nonminority employees have the right to intervene to challenge the promotional remedy, but not to contest the existence of past discrimination); Bradley v. Milliken, 620 F.2d 1141, 1142 (6th Cir.1980) (representative of Hispanic community has right to intervene for the limited purpose of presenting evidence on question of de jure segregation of Hispanics); see generally Shapiro, Some Thoughts on Intervention Before Courts, Agencies, and Arbitrators, 81 Harv.L.Rev. 721, 752-56 (1968) (discussing limited intervention as of right). Examining an applicant’s asserted interest in terms of discrete phases of an action seems particularly appropriate in institutional litigation. In institutional reform litigation, while only some individuals may be held liable for the unlawful conduct, and thus have an interest in the determination of liability, a larger number of persons’ interests may be infringed on at the remedial stage of the litigation. See, e.g., Equal Employment Opportunity Commission v. American Telephone and Telegraph Co., 506 F.2d 735 (3d Cir.1974).
C.
We thus turn to the District Attorney’s contention that he has a right to intervene to litigate whether the conditions [600]*600in the prison are unconstitutional. Under Pennsylvania law, the City defendants are vested with the responsibility of managing the prison system. It is the City, therefore, that would incur any liability, including attorney’s fees under 42 U.S.C. § 1988 (1982), if the prison conditions were found to violate the Constitution.
The District Attorney, on the other hand, has no legal duties or powers with regard to the conditions in the Philadelphia prison system. He has no function in the administration of the prisons. His participation in the liability stage could not contribute to a greater understanding of the issues involved in this phase of the litigation.
Moreover, after five years in the federal courts, and fifteen years in the state courts, the City officials charged both with the duty of managing the prisons and presumably an awareness of the situation, have concluded that they should not litigate the issue of the constitutionality of the conditions in the prisons. This combination of circumstances leads us to conclude that the District Attorney, who has no role in the prison management and cannot be held liable for any unlawful conditions, does not have the right to prevent the City from effectuating its reasoned judgment that it is best not to litigate the action. Otherwise stated, the District Attorney has no interest entitling him to litigate the plaintiffs’ contention that the conditions in the Philadelphia prison system are unconstitutional.
D.
We now address the more difficult question presented on appeal: whether the District Attorney has the right to intervene as a party in the formation of the terms of the settlement agreement in this case. The district court denied the District Attorney’s motion because it found that the enforcement of the Commonwealth’s penal statutes was not an issue in this case. It further stated that “[wjhile the final disposition of this action — either by settlement or by injunctive relief granted after a finding of unconstitutional conditions — could have some effect on the District Attorney’s enforcement function, it is not the kind of direct, substantial interest that permits intervention as of right.” The District Attorney asserts that the court committed a legal error in so concluding.
As discussed above, the District Attorney has the power and duty to advocate bail levels, to prosecute defendants, to recommend sentences once defendants are convicted, to defend convictions on appeal, and to defend challenges to the Commonwealth’s penal statutes. He is the official who represents the Commonwealth’s interests in criminal law enforcement.
The consent decree presented to, and approved by, the district court does not alter any of the duties enumerated above. The District Attorney is not prevented from performing his statutory duties. He is not obligated to take any action, or refrain from any action, by the decree; moreover, he could not be held in contempt under this decree. In short, none of his enumerated legal duties are taken away by the settlement approved in this case.
Because the consent decree does not alter the District Attorney’s legal duties, Cobb v. Aytch, 539 F.2d 297 (3d Cir.1976), cert. denied sub nom. Engelfried v. Aytch, 429 U.S. 1103, 97 S.Ct. 1130, 51 L.Ed.2d 554 (1977), does not control this case. In Cobb, inmates of the Philadelphia prisons challenged the transfer of prisoners between the county and state prisons and named as defendants two state officials — the Attorney General and the Commissioner of Corrections — and three city officials — the District Attorney, the Commissioner of Police, and the Superintendent of the Philadelphia Prisons. The district court approved an agreement reached between the state officials and the plaintiffs, and the city officials appealed. We held that the court erred in approving the settlement over the objections of the Superintendent because, although the decree did not mention him, it took away his right, granted by state statute, to petition the state authorities to accept inmate transferees from the Philadelphia prisons. Id. at 300-01. In this case, by contrast, the decree does not limit the District Attorney’s exercise of his statutory duties.
[601]*601The District Attorney argues, however, that although the decree does not impinge expressly on his functions, his powers will be affected as a practical matter by the operation of the decree. In particular, he argues that the prison cap will hinder his ability to prosecute cases because some of the pre-trial detainees released will not appear for trial. He also asserts that if the City is forced to refuse admissions to the prisons, his role as a prosecutor will be rendered meaningless as to those not admitted. Finally, he asserts that his participation as a party is necessary to protect the public interest.
We agree with the District Attorney that Rule 24(a)(2) directs the courts to consider the practical consequences of the litigation in passing on an application to intervene as of right. As one court has noted, “the court is not limited to consequences of a strictly legal nature ... [but] may consider any significant legal effect on the applicant’s interest____” National Resources Defense Council, Inc. v. United States Nuclear Regulatory Commission, 578 F.2d 1341, 1345 (10th Cir.1978). Courts thus have found that an applicant has a sufficient interest to intervene when the action will have a significant stare decisis effect on the applicant’s rights, e.g., Smith v. Pangilinan, supra, 651 F.2d at 1325, or where the contractual rights of the applicant may be affected by a proposed remedy, e.g., Little Rock School District v. Pulaski County Special School District, No. 1, 738 F.2d 82, 84 (8th Cir.1984); Equal Employment Opportunity Commission v. American Telephone and Telegraph Co., supra, 506 F.2d at 741-42.
At the same time, however, to have an interest sufficient to intervene as of right, “the interest must be ‘a legal interest as distinguished from interests of a general and indefinite character.’ ” United States v. American Telephone and Telegraph Co., 642 F.2d 1285, 1292 (D.C.Cir.1980), quoting Radford Iron Co. v. Appalachian Elec. Power Co., 62 F.2d 940, 942 (4th Cir.1933). In many cases, especially class action litigation, the disposition of the action will have some impact on the interests of third parties. To intervene as of right as a party to the litigation, however, the applicant must do more than show that his or her interests may be affected in some incidental manner. Rather, the applicant must demonstrate that there is a tangible threat to a legally cognizable interest to have the right to intervene. See, e.g. United States v. Perry County Board of Education, 567 F.2d 277, 279 (5th Cir.1978).
Ceilings on prison population are a common rémedy in prison overcrowding cases. See, e.g., Inmates of Allegheny County Jail v. Wecht, 754 F.2d 120 (3d Cir.1985); Badgley v. Varelas, 729 F.2d 894 (2d Cir.1984); Duran v. Elrod, 713 F.2d 292 (7th Cir.1983), cert. denied, 465 U.S. 1108, 104 S.Ct. 1615, 80 L.Ed.2d 143 (1984). To the extent that the ceiling on the prison population, and any resultant release of inmates, may be required to maintain constitutional conditions in the prisons, the District Attorney has no legally protected interest in causing the constitutionally-imposed maximum to be exceeded. Simply stated, he can have no interest in assuring the incarceration of persons under unconstitutional conditions. Cf Stotts v. Memphis Fire Dept., 679 F.2d 579, 582 (5th Cir.), cert. denied, 459 U.S. 969, 103 S.Ct. 297, 74 L.Ed.2d 280 (1982) (“There is no legally cognizable interest in promotional expectations which presumptively could only occur as the result of discriminatory practices.”). The District Attorney argues, however, that the attempt by the City to agree to a prison ceiling interferes with his duties and thus, he has a right to intervene in this action.
We are persuaded that the District Attorney’s argument that he has a right to be a party to this litigation overstates his role as the law enforcement officer of the Commonwealth. But see Jackson v. Hendrick, supra 446 A.2d at 232-34 (1982) (Nix, J., dissenting) (release of pretrial detainees affects the District Attorney’s functions).12 [602]*602The District Attorney’s argument assumes that he has the right to oversee the entire criminal justice system in Philadelphia. Under Pennsylvania law, however, a number of different actors have legal duties with respect to the system of criminal justice. For example, it is the duty of the state court judges to determine the bail status of those accused, 42 Pa.Cons.Stat. Ann. § 1123 (Purdon Supp.1986), and to set the sentences of those convicted. 42 Pa. Cons.Stat.Ann. § 9701 et seq. (Purdon 1982 and Supp.1986. The Mayor and City Council, moreover, have the authority to determine the size of the police force through their control of the City budget. 351 Pa. Admin.Code §§ 2.2-300, 4.4-101 (1986). Any action by one of actors in the system is likely to have some repercussions in terms of the other actors’ duties.
We must respect the boundaries that the Commonwealth has chosen to draw as to the responsibilities of its public officials. But we decline to equate the District Attorney’s function as the spokesperson for Pennsylvania’s interest in criminal prosecutions with the responsibility for policing the entire criminal justice system. Although we agree with the District Attorney that the decree may result in some people not appearing for their scheduled trial dates and some individuals not having to post bond before being released, this by-product of the decree is not sufficient to give the District Attorney the right to become a party to any consent decree entered in this case. Cf Graddick v. Alabama, 453 U.S. 928, 934-35, 102 S.Ct. 4, 8-9, 69 L.Ed.2d 1025 (1981) (Powell, J., in chambers) (expressing his doubt that the Attorney General of Alabama had standing to seek a stay of a court order releasing inmates from prison when the Governor, who was vested with the responsibility for the prison system, opposed the Attorney General’s motion); but cf Id. at 941-43, 102 S.Ct. at 11-12 (Rehnquist, J., in chambers) (explaining that he believes that the Attorney General has standing in light of his interest in law enforcement and the fact he was a party to the litigation).
Moreover, we reject the District Attorney’s assertion that the City officials will be insensitive to concerns for public safety. Experience has demonstrated in similar cases that the officials in charge of the prisons are attuned to such concerns and will return to the court to seek a modification of the decree if the ceiling threatens the safety of the public. See Duran v. Elrod, 760 F.2d 756 (7th Cir.1985).
We therefore conclude that the District Attorney has not asserted a sufficient interest to intervene in this action as of right. This conclusion, moreover, is consistent with the approach that other circuits have taken when a public official has petitioned to intervene as of right. Where the public official has demonstrated only a general interest in the litigation, his motion to intervene has been denied. See, e.g., Blake v. Pallan, supra, 554 F.2d at 953 (state securities commissioner does not have a sufficient interest in class action suit merely because the action contains some pendent state claims); People of State of California v. Tahoe Regional Planning Agency, supra, 792 F.2d at 782.
On the other hand, courts have found that the official had a sufficient interest to intervene in cases in which the subject of the suit came within the scope of his official duties. In Smith v. Pangilinan, supra, for example, the Ninth Circuit concluded that the Attorney General, as the official charged with the administration of the nation’s immigration laws, had a sufficient interest to intervene in an action in which the plaintiffs sought to have the court determine whether they were persons who would, in the future, be able to become United States citizens. See also Hines v. D Artois, supra, 531 F.2d at 738 (state examiner for the Civil Service has right to intervene where relief sought by plaintiff involved changes in the civil service examination); Neusse v. Camp, supra, 385 F.2d at 700 (state banking commissioner had an [603]*603interest in action in which the federal law incorporated the substance of the state law because the litigation involved “the nature and protection of the state policy”). Because we believe that the District Attorney’s interests fall within the first category of cases, we find that the district court did not abuse its discretion in denying the motion to intervene as of right.
Given our conclusion that the District Attorney does not have a sufficient interest to intervene of right as a party in this action, it is not necessary to review the correctness of the district court’s determinations that the District Attorney did not meet the other requirements of the intervention rule. Moreover, we need not reach the issue of whether the district court abused its discretion in denying the District Attorney’s motion for permissive intervention because he "has not argued this issue on appeal and we deem it waived. See United States v. Hooker Chemical & Plastics Corp., supra, 749 F.2d at 969.
We would add that, although the District Attorney is not entitled to intervene as of right, we think it was entirely appropriate for the district court to permit the District Attorney to be heard on the terms of the consent decree, however his status may be otherwise legally characterized. Indeed, permitting persons to appear in court, either as friends of the court or as interveners for a limited purpose, may be advisable where third parties can contribute to the court’s understanding of the consequences of the settlement proposed by the parties. See, e.g., Kirkland v. New York State Dept. of Correctional Services, 711 F.2d 1117, 1125-27 (2d Cir.1983), cert. denied sub nom. Althiser v. New York State Dept. of Correctional Services, 465 U.S. 1005, 104 S.Ct. 997, 79 L.Ed.2d 230 (1984) (permitting nonminority employees to intervene to object to the affirmative action provisions in a proposed consent decree).
III.
The District Attorney also appeals the order of the district court approving the proposed consent decree. The source of the district court’s authority to enter a consent decree is the parties’ agreement. See Local No. 93, International Association of Firefighters v. City of Cleveland, — U.S. -, 106 S.Ct. 3063, 3076, 92 L.Ed.2d 405 (1986). As the Supreme Court has stated,
Consent decrees are entered into by parties after careful negotiation has produced agreement on their precise terms. The parties waive their right to litigate the issues involved in the case and thus save themselves the time, expense and inevitable risk of litigation. Naturally, the agreement reached normally embodies a compromise; in exchange for the saving of cost and elimination of risk, the parties each give up something they might have won had they proceeded with the litigation.
United States v. Armour & Co., 402 U.S. 673, 681-82, 91 S.Ct. 1752, 1757, 29 L.Ed.2d 256 (1971).
Because a consent decree is an agreement between the parties to settle a case, one who is properly denied intervention cannot appeal the merits of the case. See Commonwealth of Pennsylvania v. Rizzo, supra, 530 F.2d at 508. The District Attorney’s appeal of the merits, therefore, must be dismissed.13
In dismissing the District Attorney’s appeal of the consent decree, we do not intend to imply that a district court can avoid its independent obligation to determine that, as a matter of subject matter jurisdiction, such terms “ ‘come within the general scope of the case made by the pleadings.’ ” Local No. 93, supra, — U.S. -, 106 S.Ct. at 3077, 92 L.Ed.2d 405, quoting Pacific R. Co. v. Ketchum, 101 U.S. (11 Otto) 289, 297, 25 L.Ed. 932 (1880); Sansom Committee v. Lynn, 735 F.2d 1535, 1538 (3d Cir.); cert. denied sub nom. Trustees of University of Pennsylvania v. Sansom [604]*604Committee, 469 U.S. 1017, 105 S.Ct. 431, 83 L.Ed.2d 358 (1984). That the relief comes within the scope of the pleadings, however, is not in question here. Moreover, because we conclude that the merits of the case are not properly before us, we are not called upon to decide in this case what legal and factual foundations are required for the district court to enter a consent decree.14
IV.
In light of the foregoing, the order of the district court denying the District Attorney’s motion to intervene as of right will be affirmed.
The appeal of the District Attorney from the order of the district court approving the consent decree will be dismissed.