Opinion
BORDEN, J.
The principal issue in this certified appeal is whether a dispute regarding the legality of certain provisions of the town charter of the named defendant, the town and borough of Naugatuck, was rendered moot as a result of subsequent amendments to the charter. In general terms, the provisions at issue concerned the service of the mayor on the plaintiff board of education of the town and borough of Naugatuck (board), and separate referenda on both the town and board budgets. Following our grant of certification,1 the board appeals from the judgment of the Appellate Court dismissing the defendants’2 appeal, vacating the judgment of the trial court, and remanding the case to that court with direction to dismiss the board’s action. [411]*411Board of Education v. Naugatuck, 58 Conn. App. 632, 638, 755 A.2d 297 (2000). Both the board and the defendants claim that an actual controversy regarding the substantive validity of the charter provisions has existed at all times relevant to the underlying action and appeal process. We conclude that the controversy is not moot and, accordingly, we reverse the judgment of the Appellate Court.
The board sought a declaratory judgment3 invalidating two amendments to the Naugatuck town charter that had been adopted in 1996.4 Both the board and the defendants moved for summary judgment and entered into extensive factual stipulations to narrow the issues for consideration by the trial court. The trial court granted summary judgment in favor of the board, invalidating the town charter amendments at issue. The defendants appealed from the trial court’s judgment to the Appellate Court. Without ruling on the merits, the Appellate Court determined that the 1996 amendments to §§ 3.18 and 14 of the town charter had been superseded by additional provisions presented to, and approved by, the Naugatuck electorate in 1998. Board of Education v. Naugatuck, supra, 58 Conn. App. 638. Accordingly, the Appellate Court dismissed the appeal [412]*412for lack of subject matter jurisdiction and remanded the case to the trial court with direction to dismiss the board’s action as moot. Id., 641. This appeal followed.
This case presents an unusual situation because all of the parties to the appeal agree, as they did in the Appellate Court, that the question of the validity of §§3.18 and 14 of the town charter was not rendered moot by a subsequent amendment to the town charter in 1998. Nonetheless, because mootness implicates a court’s subject matter jurisdiction; Sadlowski v. Manchester, 206 Conn. 579, 583, 538 A.2d 1052 (1988); we are required, as was the Appellate Court, to address the question of justiciability.
The following facts and procedural history, as stated by the Appellate Court, are relevant to the disposition of this appeal. “In April, 1997, the board commenced [a] declaratory judgment action against the defendants seeking to have the 1996 amendments to § 3.18 and § 14 of the Naugatuck charter declared invalid and void ab initio. The board’s second amended complaint alleged that on or about November 5, 1996, the defendants submitted the following proposed charter amendments, among others, in the form of questions, to the Naugatuck electorate. Question three asked, ‘Shall the Charter be revised to allow up to (3) three separate budget referend[a] for both the Town Operating Budget and the Board of Education Budget?’ Question four asked, ‘Shall the Charter be revised to provide that the terms of office for members elected to the Board of Education at the May 1997 election shall be for (2) two years, and that each term which shall expire thereafter shall also be elected for (2) two years?’ Question five asked, ‘Shall the Charter be revised to provide for a nine member Board of Education, one of whose members shall be the Mayor or his designee, effective at the May 1997 election?’
[413]*413“These questions, the complaint alleged, related to §§ 3.18 and 14 of the Naugatuck charter and the board’s responsibility pursuant to General Statutes § 10-220 to manage the public schools. The complaint also alleged that the board is vested with authority to carry out the educational policies of the state in Naugatuck, and that the membership amendment improperly altered the composition of the board, placed a member on the board who was not elected (the mayor), reduced the term of the members of the board and impaired the board’s ability to obtain annual funding. The complaint further alleged that § 14 of the charter concerns the process by which the Naugatuck electorate can seek a referendum on the Naugatuck proposed budget, which is comprised of Naugatuck’s operating budget and the board’s annual budget, and that the budget amendment was invalid.
“The complaint further alleged that the defendants failed to follow the statutorily mandated procedures with which a municipality must comply to supersede a special act charter such as the one that serves as Naugatuck’s organic law. ... It also alleged that because the defendants failed to comply with the requirements of General Statutes § 7-191 prior to submitting the proposed amendments to the electorate, the amendments to the Naugatuck charter were invalid and without effect. In addition, the complaint alleged that although the defendants knew or should have known that they had failed to comply with the statutory requirements, following the November 5, 1996 election, they took affirmative steps to implement the alleged invalid and illegal amendments to the charter. The complaint prayed for a judgment declaring the amended provisions of the charter invalid and void ab initio.
“By the early spring of 1998, the parties had filed motions for summary judgment. They also stipulated to the facts underlying their dispute and to the issues [414]*414to be determined by the court. Because there were no genuine issues of material fact, the court was presented with a question of law. . . . Specifically, the court had to determine the validity of the amendments to §§ 3.18 and 14 of the charter. The facts to which the parties stipulated were, among other things, that the board had standing to bring the action, that the board had complied with Practice Book § 17-55, that the board would not pursue any claim that the defendants had failed to comply with the procedural requirements for a charter revision as required by statute, [and] that the court’s ruling on the motions for summary judgment would be dispositive of all procedural and substantive issues .... [The parties also reached an agreement regarding] the text of §§ 3.18 and 14 of the charter immediately prior to the November 5, 1996 election, the text of the amended charter provisions subsequent to the election, the board’s position with respect to the amended provisions, the defendants’ position with respect to the amended provisions, and [the existence of] an actual and bona fide dispute concerning the amended provisions of the charter.” (Citations omitted.) Board of Education v. Naugatuck, supra, 58 Conn. App. 634-36. Because the defendants seemed to concede the invalidity of the language in § 3.18 of the charter relating to the service of the mayor’s “designee” on the board and represented that a new amendment would be presented to the electorate without this language, the board also agreed to withdraw its claim regarding this portion of the charter provision.
“The court’s memorandum of decision was filed on September 29,1998. The court found the following facts to be undisputed. The charter is the organic law of Naugatuck. Section 3.18 of the charter prescribes the number of board members, their method of election and the length of their terms. Section 14 of the charter sets forth the process by which the Naugatuck electorate can seek a referendum on the proposed budget, [415]*415which includes both the Naugatuck operating budget and the board’s annual budget. Sections 3.18 and 14 of the charter were amended by the electorate on November 5, 1996, and the defendants took affirmative steps to give effect to the amendments. The court also found that the board had standing to bring the action and that it had complied with Practice Book § 17-55. The court further found that there were bona fide and substantial questions in dispute concerning the amended provisions of the charter that had led to uncertainty as to the parties’ rights and relations, and that the challenge to the amendments presented a live controversy.” Id., 636-37. Based upon its findings of fact and its review of the applicable law, the trial court rendered summary judgment in favor of the board and declared the 1996 amendments to §§ 3.18 and 14 of the town charter invalid. Thereafter, the defendants appealed.
“At oral argument before [the Appellate Court] and in their supplemental brief, the defendants acknowledged that they had not complied with all of the statutory requirements in amending the charter provisions at the November, 1996 election, but claimed that the parties had stipulated that the board would not pursue any claims that the defendants had failed to comply with the statutory procedural requirements for approving the charter amendments. The defendants attempted to correct the deficiencies in the 1996 charter amendment process by engaging in another charter revision process, culminating in the 1998 election. In the appendix to their supplemental brief, the defendants provided a certified copy of the moderator’s return for the November 3, 1998 charter referendum, revealing that the electorate had voted on and approved three questions relating to the membership and budget amendments to the charter.” Id., 637-38. The Appellate Court concluded that because the 1996 amendments had been superseded by those approved by the Naugatuck electorate [416]*416in 1998, the issues presented by the parties were moot. Id., 638. Accordingly, the Appellate Court dismissed the appeal for lack of subject matter jurisdiction. Id., 633, 641.
In this court, the board, joined by the defendants, claims that at all times relevant to both the underlying action and subsequent appeals there has been an actual controversy regarding the legality of the charter amendments. Specifically, the board contends that this case fits squarely within the four part test for justiciability established in State v. Nardini, 187 Conn. 109, 445 A.2d 304 (1982). We agree.
“Because courts are established to resolve actual controversies, before a claimed controversy is entitled to a resolution on the merits it must be justiciable. Justiciability requires (1) that there be an actual controversy between or among the parties to the dispute ... (2) that the interests of the parties be adverse ... (3) that the matter in controversy be capable of being adjudicated by judicial power . . . and (4) that the determination of the controversy will result in practical relief to the complainant.” (Citations omitted; internal quotation marks omitted.) Id., 111-12.
The first Nardini factor—the requirement of an actual controversy—is premised upon the notion that courts are called upon to determine “existing controversies, [and therefore] may not be used as a vehicle to obtain judicial opinions on points of law.” (Internal quotation marks omitted.) Id., 112. An actual controversy exists “where there is an actual bona fide and substantial question or issue in dispute or substantial uncertainty of legal relations which requires settlement . . . .” (Internal quotation marks omitted.) Pamela B. v. Ment, 244 Conn. 296, 323, 709 A.2d 1089 (1998). It is well settled that the actual controversy must exist at all times during the appeal; Sobocinski v. Freedom of [417]*417Information Commission, 213 Conn. 126, 134—35, 566 A.2d 703 (1989); and that facts arising during, or subsequent to, the action in question may render such a controversy obsolete. Hartford Principals’ & Supervisors’ Assn. v. Shedd, 202 Conn. 492, 497-98, 522 A.2d 264 (1987).
In the present case, an actual controversy regarding §§ 3.18 and 14 of the Naugatuck town charter came into existence upon the amendment of those provisions in 1996. The November, 1996 election permitted, for the first time, service of the mayor on the board and separate referenda for both the board and town budgets. The substantive legality of these provisions was disputed by the parties from their inception, and ultimately was submitted to the trial court for resolution. The board alleged that § 3.18 of the charter, permitting the mayor to serve on the board, violated General Statutes §§ 9-206a and 7-193,5 and that § 14 of the charter, dealing [418]*418with the budget referenda, violated General Statutes § 7-344.6 The board further argued that the amended [419]*419charter provisions interfered with the board’s independence, integrity and ability to effectuate its duties as delegated to it by the state under General Statutes §§10-[420]*420220 and 10-241.7 The defendants, however, maintained [421]*421that the mayor’s service on the board was not contrary [422]*422to, but rather consistent with, § 9-206a, and that the adoption of separate budget referenda was authorized by General Statutes §§ 7-194 and 7-198.8
The parties stipulated that there were actual, bona fide and substantial questions in dispute regarding the amended charter provisions that presented a live controversy for the trial court’s resolution. The trial court, in its memorandum of decision, determined that such bona fide and substantial questions existed. The trial [423]*423court also determined that those questions led to uncertainty as to the parties’ rights and relations, that the challenge to the charter provisions met the requirement of a true controversy, and that judicial resolution of the matter was proper.
We conclude that the actual controversy recognized by both the parties and the trial court survived the 1998 amendments to the Naugatuck town charter and remains in existence to date. We reach this decision without doing violence to that body of case law, previously referenced, which recognizes that certain acts may intervene while an appeal is pending to render a matter moot. See Hartford Principals’ & Supervisors’ Assn. v. Shedd, supra, 202 Conn. 497-98. The 1998 amendments did not, in any way, alter those aspects of § § 3.18 and 14 of the town charter that were contested by the parties and ruled on by the trial court. The only substantive result of the 1998 amendments was to delete the language present in the 1996 version of § 3.18 that permitted the mayor’s designee to serve on the board. The parties, however, had stipulated to withdraw any claim regarding that language from the trial court’s consideration; only the questions of the legality of the may- or’s service on the board and of separate budget referenda were before the trial court. Because the 1998 amendments did not cure the alleged underlying defects with respect to these two provisions, there remains an actual controversy capable of, and requiring, adjudication. See, e.g., Cheshire Taxpayers’ Action Committee, Inc. v. Guilford, 193 Conn. 1, 4 n.7, 474 A.2d 97 (1984) (plaintiffs case not moot because method of budget approval contained in proposed ordinance was not substantially same as method set forth in amended charter).
In addition to the presence of an actual controversy, Nardini requires that the interests of the parties be adverse before a matter is justiciable. State v. Nardini, supra, 187 Conn. 112. The requirement of adversity [424]*424“ensure [s] that . . . judicial decisions which may-affect the rights of others are forged in hot controversy, with each view fairly and vigorously represented.” Maloney v. Pac, 183 Conn. 313, 320, 439 A.2d 349 (1981). As previously discussed, both parties disagree regarding the substantive legality of §§ 3.18 and 14 of the charter since their amendment in 1996. Because the 1998 amendments are, with respect to the challenged provisions, virtually identical to those enacted in 1996, the interests of the parties with respect to the challenged provisions are unchanged and remain adverse.
The third requirement for justiciability under Nardini is that the matter in controversy be capable of resolution by judicial authority. State v. Nardini, supra, 187 Conn. 112. Satisfaction of this prong of the Nardini test often turns on whether the issue presented is properly characterized as a “political question” that falls within the exclusive province of the legislature. See, e.g., Nielsen v. State, 236 Conn. 1, 7, 670 A.2d 1288 (1996). Where adjudication of the matter would tend to violate the doctrine of separation of powers, it is deemed political in nature and the court should abstain from its resolution. Id. We have stated that “[wjhether a controversy so directly implicates the primary authority of the legislative or executive branch, such that a court is not the proper forum for its resolution, is a determination that must be made on a case-by-case inquiry.” (Internal quotation marks omitted.) Id. Characteristics of a political question have been found to include “a textually demonstrable constitutional commitment of the issue to a coordinate political department; or a lack of judicially discoverable and manageable standards for resolving [the issue]; or the impossibility of deciding without an initial policy determination of a kind clearly for nonjudicial discretion; or the impossibility of a court’s undertaking independent resolution without expressing lack of the respect due coordinate branches of government; [425]*425or an unusual need for unquestioning adherence to a political decision already made; or the potentiality of embarrassment from multifarious pronouncements by various departments on one question.” (Internal quotation marks omitted.) Id.
We conclude that the substantive validity of the disputed Naugatuck charter provisions is a matter capable of judicial resolution. There is no exclusive grant of authority to the municipality that would preclude the court from determining whether §§3.18 and 14 of the town charter are illegal as enacted. In deciding the merits of this case, the court simply would be called on to perform one of its most basic and routine functions: statutory interpretation. See Flewellyn v. Hempstead, 47 Conn. App. 348, 350, 703 A.2d 1Í77 (1997) (where “the controversy raises issues of . . . statutory interpretation of the kind regularly entertained by courts,” it may not present political question [internal quotation marks omitted]). Furthermore, the standards by which the legality of the charter provisions are to be measured are concrete, straightforward and grounded in our state law, and, as previously stated, an actual controversy exists that demands resolution. As a result, this case is ripe for adjudication. In reaching this conclusion, we are sensitive to the fact that the charter provisions, as enacted, represent the popular will of the Naugatuck electorate and thus directly implicate the political and legislative process. We have never recognized connection to the political sphere, however, as an independent basis for characterizing an issue as a “political question”; Nielsen v. Kezer, 232 Conn. 65, 77 n.19, 652 A.2d 1013 (1995); and we decline to do so in the present case.
The fourth prong of the Nardini test asks whether the court is capable of granting the plaintiff any practical relief. State v. Nardini, supra, 187 Conn. 112. Typically, inquiry into that aspect of justiciability is considered in conjunction with the first Nardini factor, [426]*426the existence of an actual controversy. As a general rule, we have held that where the underlying dispute has not been resolved, the court is capable of affording the plaintiff relief. See Waterbury Hospital v. Connecticut Health Care Associates, 186 Conn. 247, 251, 440 A.2d 310 (1982) (where complained of conditions no longer exist, injunctive relief no longer appropriate and court cannot fashion remedy); Connecticut Natural Gas Corp. v. Dept. of Consumer Protection, 43 Conn. App. 196, 203-204, 682 A.2d 547, cert. denied, 239 Conn. 938, 684 A.2d 707 (1996) (where passage of public act did not settle parties’ differences, court could grant practical relief).
There remains a controversy in the present case over whether the mayor legally may serve on the board, and whether the town legally may have separate referenda on the board and town budgets. Furthermore, in its initial complaint, the board sought declaratory relief invalidating §§3.18 and 14 of the town charter and requested that the court order those provisions reinstated as they existed prior to the 1996 amendments. On appeal to this court, the board again has enunciated a specific remedy: reversal of the Appellate Court’s decision and reinstatement of the defendants’ appeal. Because a controversy regarding the charter provisions remains in effect, and because the board has articulated a request for specific relief, we conclude that the trial court was able to afford practical relief in this case.
We disagree, therefore, with the conclusions of the Appellate Court that: (1) consideration of the merits was mooted by the passage of the 1998 amendments to §§ 3.18 and 14 of the town charter; and (2) the trial court improperly ruled on a hypothetical question in considering the validity of § 3.18 of the charter in the absence of the language pertaining to service of the mayor’s “designee” on the board. Board of Education v. Naugatuck, supra, 58 Conn. App. 638-40. With respect [427]*427to the first conclusion, we have rejected the general proposition that “a case must be dismissed as moot when the statute involved in the litigation is amended or a new statute is enacted.” Hilton v. New Haven, 233 Conn. 701, 726, 661 A.2d 973 (1995). The crucial inquiry under Hilton is whether the court may still grant practical postamendment relief. Id. That the new ordinance differs from the old ordinance in certain respects does not, in and of itself, moot consideration of the original ordinance. Northeastern Florida Chapter of the Associated General Contractors of America, v. Jacksonville, 508 U.S. 656, 662, 113 S. Ct. 2297, 124 L. Ed. 2d 586 (1993). Nor will a subsequent amendment that “alterfs] the law in some insignificant respect.” (Internal quotation marks omitted.) Id., 670 (O’Connor, J., dissenting). Rather, where a substantive controversy continues to persist even after amendment of a statute, the controversy is not moot and remains justiciable. Sable Communications of California, Inc. v. Federal Communications Commission, 492 U.S. 115, 131, 109 S. Ct. 2829, 106 L. Ed. 2d 93 (1989) (where contested, substantive statutory prohibitions against obscene commercial telephone messages remained same under subsequent amendment, case not moot); Heckler v. Mathews, 465 U.S. 728, 733 n.3, 104 S. Ct. 1387, 79 L. Ed. 2d 646 (1984) (because Congress’ amendment to pension offset provision did not affect central dispute, case justiciable); Brockington v. Rhodes, 396 U.S. 41, 42, 90 S. Ct. 206, 24 L. Ed. 2d 209 (1969) (where party argued unconstitutionality of any percentage requirement for voter’s signatures in excess of 1 percent, amendment reducing necessary percentage from 7 percent to 4 percent did not render case moot); Panama Refining Co. v. Ryan, 293 U.S. 388, 413-14, 55 S. Ct. 241, 79 L. Ed. 446 (1935) (action to enjoin enforcement of executive regulations was not made moot by amendments of regulations, adopted pending litigation, which [428]*428continue in force requirements complained of and presented same question as before); cf. St. Pierre v. Solnit, 233 Conn. 398, 398-99, 658 A.2d 977 (1995) (where challenged departmental policy amended to grant complainants substantive relief sought, action rendered moot); Roy v. Mulcahy, 161 Conn. 324, 327-28, 288 A.2d 64 (1971) (dispute regarding legality of statute providing that only corporals could take examination for state police sergeant rendered moot after amendment that eliminated reference to rank; because provision substantively revised to eliminate controversy, regulation “as it existed prior to the amendment . . . [was] of no further force and effect”). We conclude that the substantive questions regarding §§3.18 and 14 of the town charter survived the 1998 amendments. Because the challenged portions of those provisions, as amended in 1996, were unchanged by the 1998 ordinance, the dispute regarding their legality remains justiciable.
The Appellate Court also concluded that, because the trial court failed to consider whether the mayor’s designee could serve on the board, the legality of § 3.18 of the town charter presented an academic question rather than an actual controversy. Board of Education v. Naugatuck, supra, 58 Conn. App. 639-40. The Appellate Court reasoned that, in ruling on the membership amendment without consideration of the “ ‘or designee’ ” language, the trial court improperly considered a hypothetical, rather than existing, act. Id. We disagree.
The board’s complaint initially questioned whether the mayor’s designee lawfully could serve on the board. The board specifically abandoned this claim, however, upon the defendants’ representation that they would resubmit § 3.18 of the town charter to the electorate without the “offending language.” In the present case, neither party raised the merits of whether the mayor’s designee could serve on the board in its motion to dismiss. In fact, the board even acknowledged, in its [429]*429brief to the trial court, that “since the defendants are currently in the process of rectifying [the] deficiency with a new charter revision eliminating the ability of a designee to serve on the [b]oard, the [board] does not raise this defect to the court in the instant motion for partial summary judgment.” These facts persuade us that any claim regarding this particular portion of § 3.18 was abandoned by the parties and properly removed from the trial court’s consideration.
Even more persuasive is the parties’ agreement that the language pertaining to service of the mayor’s designee on the board was invalid and should be removed, an agreement that was incorporated into the stipulations presented to the trial court. Because both the board and the defendants concurred regarding this issue and, essentially, resolved the matter of their own accord, the validity of that provision no longer presented an actual controversy capable of judicial resolution. Accordingly, we conclude that the validity of § 3.18 of the town charter was not an academic question, but rather an actual controversy that the trial court was correct in resolving.
The judgment of the Appellate Court is reversed and the case is remanded to that court for further proceedings according to law.
In this opinion the other justices concurred.