EDMONDSON, J.
11 Two issues are presented in this appeal. The first is whether a taxpayer should have been allowed to intervene in a District Court proceeding that was brought to obtain a declaratory judgment stating that certain public expenditures and financing were lawful. A portion of this first issue involves whether a gui tam action may be brought on behalf of a public trust and against its officers. The second is whether this appeal is moot because the parties proceeded to obtain a declaratory judgment in the District Court after Taxpayer was not allowed to intervene. We address the second issue first because Appellees' claim for mootness would make unnecessary a decision on the first issue if they are correct, and because the mootness issue involves the same issue for both a mootness analysis and a determination whether a gui tam plaintiff should be allowed to intervene in a gut tam proceeding.
12 Tulsa Hills, LL.C., (THL) sought to create a shopping center in Tulsa, Oklahoma. The City of Tulsa (or City) established a Tax Increment District, 62 0.8.2001 § 861, and accompanying project plan pursuant to the Local Development Act, 62 0.$.2001 §§ 850-869. This plan included the site for the Tulsa Hills Shopping Center created by THL. THL sought the City's assistance to finance "infrastructure improvements" at the Tulsa Hills Shopping Center. The improvements included drainage for rain, a public road, a sanitary sewer mainline, a water line, and road improvements in and adjacent to the property. The City Council for Tulsa authorized the Tulsa Industrial Authority (or TIA) to issue and sell tax apportionment bonds totaling 18.5 million dollars, 18.5 million of the proceeds to be transferred to THL.
13 Taxpayer argued that ad valorem and sales taxes attributed to a tax increment district would be used to pay for bonds which had been issued by a public trust to provide money to a developer building a retail outlet. Taxpayer alleged that from the $18,500,000.00 obtained from the bonds, $13,500,000.00 would be given to the developer. The developer would use those funds for: (1) on the developer's property, site leveling, [117]*117streets connecting to existing streets, storm water drainage for the shopping center, sanitary sewer and water extensions to the shopping center (for a total of $11,214,000.00); (2) unspecified off-site improvements (for a total of $561,000,00.); and (8) "contingencies" (for a total of $1,725,000.00). Taxpayer alleged that in order to get the Jenks school District to agree that the incremental ad valorem taxes attributed to the new shopping mall could be used for payment of the bonds, TIA and the City and the developer agreed to pay $765,000.00 to the school district from the proceeds obtained from the sale of the bonds. Taxpayer alleged that approximately $4,235,000.00 was used for reserves for debt service, underwriters and financial advisors fees, insurance and other borrowing costs.
¶ 4 Several taxpayers served a written demand on the TIA and the City of Tulsa pursuant to 62 0.S.2001 §§ 372, 3783, and alleged that the money transferred to THL violated the Oklahoma Public Trust Act, 60 O.S.Supp.2007 § 178.4 and Art. 10 § 19 of the Oklahoma Constitution. Taxpayers claimed that $ 178.4 prohibited a public trust from participating in a retail outlet, and that Art. 10 § 19 prohibited tax proceeds for a purpose other than that authorized by the voters. Taxpayers demanded that TIA and the City of Tulsa bring suit to recover the money transferred to THL.
15 TIA responded to Taxpayers' demand by filing an action in the District Court for Tulsa County against the City of Tulsa and THL, requesting a declaratory judgment affirming the legality and constitutionality of the project plan. THL and City filed answers supporting TIA's claims and request for a declaratory judgment. TIA filed a motion for summary judgment seeking "a declaratory judgment confirming the validity of the creation and financing of the Tulsa Hills Increment District in all respects."
{6 Bundren, a taxpayer (Taxpayer), sought to intervene in the declaratory judgment action. TIA, THL, and City filed objections to the request to Intervene. The trial court denied Taxpayer's motion to intervene, and a few days later the court granted and memorialized TIA's request for summary judgment. A few days after granting summary judgment the trial court memorialized its denial of Taxpayer's motion to intervene. Taxpayer filed in the District Court two petitions to vacate the judgment. Taxpayer appealed. The Court of Civil Appeals, with one judge dissenting, dismissed the appeal because Taxpayer did not seek to stay the trial court proceedings during Taxpayer's appeal. Taxpayer sought certiorari for review of the appellate court's decision and the issues in the appeal left unaddressed.
I. Motions to Dismiss and Qui Tam Relief
17 THL, City of Tulsa, and TIA filed motions to dismiss Taxpayer's appeal. They argued that the summary judgment granted to the parties decided the legality of the conduct of the City of Tulsa, and that this decision made Taxpayer's claims moot. They argued that: (1) Taxpayer did not seek a stay of the trial court proceeding during the appeal; (2) The claims presented in the declaratory judgment proceeding were merged into a judgment during the appeal; and (8) Due to the judgment on all claims (or causes of action), no claim remains pending in the trial court for the Taxpayer to intervene as a party and present the Taxpayer's interest in the litigation.
18 Taxpayer asserted that the appeal is not moot because his status as a non-party to the summary judgment process denied to him the authority to appeal the order granting summary judgment, and that as a non-party the judgment is not binding on him. He also argued that if allowed to intervene he will seek vacation of the judgment, and that he has already filed a petition to vacate in the District Court.
T9 Appellees' analysis focused on whether Taxpayer was a party in the trial court proceeding and could thus obtain a stay of the trial court proceeding pursuant to 12 O.S$.Supp.2008 § 990.4. That section states that "... a party may obtain a stay of the enforcement of a judgment, decree or final order: ... 8. While an appeal is pending in any court in or outside of this state." Id. at 990.4(A). Appellees also argued that a stay of the trial court proceeding pending an appeal is within this Court's supervisory writ [118]*118jurisdiction, and thus was an available remedy for Taxpayer. Because we hold herein that the failure to seek a stay did not moot the appeal, we need not analyze Taxpayer's available remedies for a stay.
{10 The statutory authorization for taxpayers to seek a gui tom remedy occurs after they make their gus tam demand to the public body and the public body fails to seek recovery of the money or property unlawfully paid. 62 0.98.2001 § 378.1 What if the public body does not seek recovery of the money but files a declaratory judgment proceeding to judicially validate its expenditure of the public's money? 2 Is this litigation conduct a § 373 failure to "institute or diligently prosecute ... for the recovery of any money?" In City of Oklahoma City v. Oklahoma City Urban Renewal Authority, we did not address the issue as a § 373 failure, but relied upon opinions from courts in Wyoming, Idaho, and New Jersey, and concluded that a public body's request for declaratory judgment seeking judicial validation of its actions could, in some circumstances, be a justicla-ble controversy.3
111 When is a public body's request for declaratory judgment a justiciable controversy? We indicated that justiciability was shown by the antagonistic claims (fact and law) presented by the public body, and this justiciability also demonstrated that the gui tom taxpayer did not possess a right to intervene in a proceeding and seek § 373 relief.4 The public body must raise the claims of the gui tam taxpayers by its petition seeking declaratory relief, and it must subsequently place those material facts and law before the trial court for adjudication.5 This result is required because: (1) The plain words of the statute (§ 373) are deemed to express legislative intent in the absence of any ambiguity in language;6 (2) The plain [119]*119words of § 373 state that a gut tam plaintiff's right to seek that remedy is conditioned upon the failure of the officers of a public body "to institute or diligently prosecute proper proceedings at law or in equity for the recovery of any money or property belonging to the state," and (8) Even if judicial construction could be applied to the gui tam statute (§ 878), a strict construction thereof would be applied requiring strict or literal compliance with the language in § 873 by the public body and any person acting on behalf of the public body;7 and a strict construction would be equated with a "literal" meaning of the words used in the statute.8 Our use of a justiciability test in the Tal cases and our more recent opinions satisfies one element of a controversy where § 378 relief is sought: Whether the public body diligently prosecuted a proper proceeding at law or in equity for the recovery of any money or property. The use of the justiciability test is thus a correct method for determining the propriety of gui tam taxpayers' efforts to intervene in a public body's quest for declaratory relief.9
$12 In the context of qui fam declaratory judgment proceedings we have explained that the declaratory judgment proceeding brought by the officials was "a justiciable case" where the issues presented "were legitimate, not feigned or collusive." 10 We have contrasted a "justiciable [120]*120controversy," which presents antagonistic material facts and law to the trial court by pleading and evidence, with a request for a prohibited advisory opinion.11 The fact that all parties to the declaratory judgment proceeding sought court approval of the actions taken by the officials "did not deprive the declaratory judgment proceeding of its justiciable character when the issues presented were not feigned or collusive by those seeking to uphold the public contracts." 12 While officials need not forensically adopt each and every argument of the gut tom taxpayer,13 they must fairly present the material facts and law to the trial court for adjudication, making more than a "half-hearted attempt." 14 They are not required to present unsupported factual conclusions made by the gui tam taxpayers.15 A gui tom taxpayer's qui tam interest in the litigation, and intervention therein, is contingent upon the public body presenting a controversy that is not justiciable, that is feigned or collusive, and we have explained that the burden is upon the taxpayer to show that such interest exists.16
113 The term "justiciable" refers to a lively case or controversy between antagonistic demands.17 When a party presents for adjudication antagonistic demands that are merely speculative, a prohibited advisory opinion is being requested.18 Likewise, when only non-antagonistic demands are presented, there is no "controversy" and an advisory opinion is being sought.19 In 1964, when explaining that declaratory relief is limited, to "cases of actual controversy," we referred to this as a jurisdictional component. We relied upon opinions from several jurisdictions for that concept, quoted with approval an opinion describing justiciability as necessary "in order to invoke the jurisdiction of the court," and ultimately concluded that the party's trial court petition "was insufficient to invoke the jurisdiction of the court under the [121]*121declaratory judgments act.20 Since that time the Court has frequently discussed the "jurisdiction" or "power" of the trial court invoked by a party seeking declaratory judgment relief21 We have explained that the absence of justiciability requires dismissal of the proceeding.22 We have thus linked the concept of justiciability when declaratory relief is sought with the jurisdiction of the trial court to grant such relief.
114 In summary, a gui tam taxpayer's § 373 right to intervene is based upon a public body's failure to seek recovery of the public funds at issue as specified in § 378. A public body's right to prevent intervention of the gui tom taxpayer in its declaratory judgment proceeding is based upon its diligent prosecution therein of the gui tam taxpayer's claim of illegality. Diligent prosecution of the gui tam taxpayer's claim of illegality requires the public body to plead and present for adjudication the merits of the taxpayer's claim when the public body also seeks to judicially validate its expenditure of public funds. When the public body seeks to judicially validate its expenditure of public funds, its simultaneous presentation of the gui tam taxpayer's claim makes the controversy justiciable and within the jurisdiction of the Declaratory Judgments Act. If the public body seeks to validate its contested expenditures and presents only non-antagonistic claims, then its forensic conduct possesses the quality of non-justiciability by presenting feigned or collusive issues for adjudication, and a gui tam intervenor is allowed to intervene and press for gui tom relief via antagonistic claims that make the controversy justiciable.
115 Appellees filed motions to dismiss Taxpayer's appeal for mootness. The concept of mootness is most often linked to cireumstances that result in a court's inability to grant effective relief by its appellate opinion in the controversy because it would possess characteristics of a hypothetical or advisory opinion.23 The argument advanced is that an opinion on whether Taxpayer should have been allowed to intervene would now possess the quality of an advisory opinion because the trial court granted declaratory relief and that judgment is allegedly en-foreeable against Taxpayer.
116 Clearly, if a public body's declaratory judgment controversy is justiciable, a gui tam taxpayer is not entitled to intervene, has no right of action pursuant to § 878,24 [122]*122and has no standing as a gui tam taxpayer to challenge a judgment on the merits of the justiciable controversy.25 However, if the trial court lacks justiciability because of a collusive or fraudulent controversy, a jurisdictional issue is presented.26 Our appellate opinions indicate that when a gui tam taxpayer is held entitled to § 873 intervention in the public body's declaratory judgment case, this holding also mecessarily determines that the controversy possesses the characteristics of a collusive or fraudulent proceeding (a § 373 failure to diligently prosecute for the recovery of the public's funds has occurred) and the proceeding lacks justiciability. The mootness argument herein thus becomes one stating that: A judgment in a controversy which is allegedly non-justiciable due to a collusive or fraudulent legal proceeding on the legality of the expenditure of public funds should be enforeed against a non-party taxpayer without judicial enquiry as to the fraudulent or collusive nature of the proceeding because the non-party failed to seek a stay to prevent the public body from obtaining the collusive or fraudulent judgment while non-party's appeal was pending.
T17 No citation to authority should be needed for the principle that it is against public policy for courts of this State to be used to create a collusive or fraudulent judgment authorizing the expenditure of public funds. In 1981, this Court declined to approve a collusive legal proceeding for an expenditure from the public purse.27 The mootness question before us today occurs in the context of an appeal from a proceeding in which the judgment occurred during the appeal from the proceeding in which the alleged collusive judgment occurred.28 Since the adjudication on the gut tam intervention issue also necessarily adjudicates the justicia-bility and alleged collusive nature of a proceeding that involves a judgment justifying an allegedly unlawful public expenditure, we hold that the issue of Taxpayer's gui tom intervention is not moot and an appellate decision herein will not be in the nature of a prohibited advisory opinion as to the gut tam intervention. The motions to dismiss the appeal for mootness are denied as to the Taxpayer's requested gui tam relief.
II. Qui Tam Relief and Public Trusts; An Equitable Relief Claim; Mootness and Intervention
{18 The usual dispositive issue on appeal of a trial court's order denying intervention to a gui tam taxpayer is not the merits of whether the public expenditures were lawful, but whether the public body fairly presented the gui tom taxpayer's claims to the trial court as part of a justiciable controversy.29 TIA argued that a preliminary issue be resolved: whether a gui tam statutory remedy is permissible when brought on behalf of a public trust. The record supports TIA's [123]*123statement that it is a public trust created pursuant to 60 0.8. § 176.30
$19 TIA argued that: (1) 62 O.S. 373 authorizes a gui tam remedy brought to maintain an action that "officers of the State, county, township, city, town, or school district" might maintain to recover public property; (2) Because § 373 is penal in nature and must be strictly construed, a gui tom remedy may be sought only on behalf of those entities expressly designated by § 378; (8) TIA is a public trust, and a public trust and its trustees are not listed in § 373; (4) Consequently, a gui tam remedy may not be sought on behalf of a public trust; and (5) The trial court correctly denied Taxpayer's motion to intervene.
120 The § 373 gut tam action is not a "cause of action," but a statutory remedy for recovery of a penalty for the commission or omission by a public official of a certain act based upon particular transactions or occurrences.31 The remedy is sought by a private individual on behalf of a public body.32 Section 878 is a remedy sought where "the proper officers of the state or of any county, township, city, town, or school district" have declined to seek recovery of public property after receiving notice of its alleged unlawful transfer, and a demand for its recovery has been made. Officers of a public body may be liable when a gui tam remedy is sought, and those officers are identified as officers "of the state and of any county, township, city, town or school district." 62 0.8.2001 § 372.33 No express mention is made of a public trust and its officers, and the plain language of both § 872 and § 373 is unambiguous as to the identity of the officers mentioned.34 Even if rules of judicial construction were used to identify the officers subject to liability, those rules could not be used to expand the class of individuals subject to liability in a proceeding that is penal in nature.35 We note that this result is consistent with language in 60 0.8. 2001 § 179 which states that no trustee of a [124]*124public trust shall be charged with personal liability "by reason of any act or omission committed or suffered in the performance of such trust or in the operation of the trust property.36
121 Title 60 § 176.1 states that a public trust "created in accordance with the provisions of Section 176 et seq. of this title shall be presumed for all purposes of Oklahoma Law to: ... 2. Exist as a legal entity separate and distinct from the settlor and from the governmental entity that is its beneficiary." 60 O.S8.8upp.2008 § 176.1. In some cireumstances a public trust may be deemed to be an alter ego of the public body for which it seeks to benefit, and equity may be used to disregard the trust's legal status as a distinct legal entity.37 This Court "is mindful that a public trust may be declared to be 'usory' upon a judicial finding of a sham fabricated by one to cireumvent one's obligations." 38 But no suggestion is made herein that TIA is an alter ego in a cireum-stance where equity should intervene, or that TIA is an illusory trust.
122 While we agree with TIA that no gui tom remedy may be sought on its behalf, Taxpayer also sought intervention based upon the rule that a taxpayer may intervene in a legal proceeding brought by a public body or private individual to enforce an allegedly unlawful agreement or expenditure made by the public body. In the trial court, Taxpayer argued that he should be allowed to intervene and obtain equitable relief against the TIA. He relied upon Threadgill v. Peterson, 1923 OK 662, 219 P. 389 and Kellogg v. School Dist. No. 10 of Comanche County, 1903 OK 81, 74 P. 110, 116. In Kellogg v. School Dist. No. 10 of Comanche County, supra, we noted the following:
[T}he doctrine that an inhabitant and taxpayer of a municipal corporation may maintain a suit by injunction to prevent the misappropriating of the funds of the corporation, the creation of invalid debts, the levy of unauthorized taxes, and the perpetration of official wrongs, has met the approval of such eminent and distinguished jurists as Field, Dillon, Cooley, Elliott, Campbell, Sharswood, and others, and the courts of highest resort in the United States, and in practically all the states of the Union.
Kellogg, 74 P. at 118-114.
Shortly after our pronouncement in Kellogg, we relied upon its holding and concluded that a taxpayer could use an injunction as a proper remedy to prevent the officers of a school district from issuing bonds in excess of the debt limit provided by the Oklahoma Constitution.39
123 In Threadgill v. Peterson, supra, an action was brought against a school district after labor and material had been furnished for the repair of a school building pursuant to a written contract, and the school district declined to pay the contractually specified amount due to a lack of funds. The school district answered and stated that the sum sued upon was due and unpaid, and judgment was rendered against the school district. Taxpayers claimed that the judgment was based upon a void contract and requested [125]*125relief in the form of an order vacating the judgment. The plaintiff objected and argued that "the taxpayers had no right, title, or interest in the subject-matter in question, and no authority of law for the proceeding there sought to be maintained." Id. 219 P. at 390. The Court explained that by statute:
. any person may be made a party who has or claims an interest in the controversy adverse to the plaintiff; that a taxpayer who sets up that an illegal judgment about to be rendered against a political subdivision will impose an unauthorized and illegal burden upon his property is so interested in the eye of the statute that he can maintain an injunction, if necessary, to invoke relief in equity.
Threadgill, 219 P. at 390.
The Court then stated that this right to seek equitable relief was found in § 4881, RL. 1910, now codified at 12 0.8.2001 § 1897.40
{24 More recently, in Oklahoma Public Employees Association v. Oklahoma Department of Central Services, 2002 OK 71, ¶ 10, 55 P.3d 1072, 1078, we relied upon Kellogg and five of our opinions dating from 1909, 1931, 1944, 1989, and 1999,41 and stated that a taxpayer should be allowed to seek relief in a court of equity to challenge illegal taxation or illegal expenditure of public funds. Historically, if a challenged tax is unconstitutional and the remedy at law inadequate, then equitable relief is available for complete relief because "a court of equity ... will not do justice by halves.42 However, the Legislature has made certain remedies to be required for a party seeking relief from unauthorized, excessive, or incorrect taxation, and this Court has historically required compliance with such statutes and not allowed equity to be used to subvert the statutory requirements.43
125 More than a century ago we explained that the version of § 1897 then effect "did not substantially enlarge the general powers of a court of equity, and did not create any new remedy," 44 and § 1897 is thus not an example of the legislature creating a new statutory remedy. The United States Court of Appeals for the Tenth Cireuit has noted that the equitable statutory remedy provided by 12 0.8. $ 1897 has an important role in providing taxpayers with a remedy to challenge an alleged unlawful levy or [126]*126collection of a tax, charge or assessment.45 Section 1897 provides a remedy where the Legislature has not acted to provide a specific required remedy for a particular cireum-stance, and we have explained that application of §$ 1897 will not supplant statutorily required remedies when the particular relief sought is within a required statutory remedy.46 A gui tam plaintiff has no interest in the gui tam controversy until the public entity fails to take certain actions, but a taxpayer seeking equitable relief, as a taxpayer, possesses an interest recognized by § 1897 that exists independent of the litigation conduct of public officials.
$26 In Kellogg v. School Dist. No. 10 of Comanche County, supra, we noted the objection to a taxpayer seeking equitable relief because he did not possess any interest in the controversy other than a general interest shared in common with all taxpayers. We noted that some courts did not allow a taxpayer to have a legal remedy for an injury the taxpayer suffered in common with other taxpayers, and allowed an equitable remedy only if the injury was one that peculiarly affected that taxpayer. Id. 74 P. at 112-113. We then noted the courts holding that a taxpayer could, as a mere taxpayer, obtain injunctive relief from an illegal or unauthorized tax. Id. 74 P. at 115-116. In Kellogg we did not recognize a general class of non-Hohfeldian plaintiffs47 who are allowed to bring public actions for the vindication of public rights and the correction of purely public wrongs of whatever nature.48 We ree-ognized that a taxpayer who is adversely affected in common with other taxpayers by the conduct of a public body could use equity to correct a public wrong by that public body when the wrong involved the creation of illegal debts of, and the wrongful expenditure of moneys of, the taxpayers. No suggestion is [127]*127made herein that a statutory remedy is available to Taxpayer for the particular claims made herein. We agree with Taxpayer that his allegation of unauthorized or unlawful expenditure of municipal taxes by a city and allegation of unlawful issuance of bonds by a public entity may be addressed by a proceeding brought by a taxpayer seeking equitable relief.
127 An analysis of the motions to dismiss based upon allegations of mootness due to Taxpayer's failure to seek a stay must be addressed in the context of Taxpayer seeking equitable relief and 12 O.S. § 1397. Equity does not require a useless act; 49 for example, an appeal will be dismissed as moot when a taxpayer has sought injunctive relief to prevent the issuance of bonds which were issued with a commitment of the proceeds during an appeal.50 Mootness is thus based, in part, upon the nature of the equitable relief sought. However, we must note that in Payne v. Jones, 1944 OK 86, 146 P.2d 113, another case involving 12 O.S. § 1897 where appellees sought dismissal alleging mootness, we stated that "In cases having to do with the collection of the public revenue the [appellate court's] discretion should ordinarily be exercised in favor of a decision on the merits." Id. 146 P.2d at 116 (explanatory phrase added).
128 Will an appellate opinion herein be advisory in nature with respect to any equitable relief sought by Taxpayer? Taxpayer's Answer filed in the District Court as Intervenor stated that the bonds had already been issued at that time, and he did not seek to use equity for preventing the bonds to be issued. Taxpayer sought an order canceling the contractual obligations of the City and TIA, and stated that appropriate relief could be a money judgment to retire the bonds. Taxpayer thus raised several issues, including, but not limited to, the propriety of equity for canceling the issued bonds in these cireumstances, and granting relief in the form of an order compelling payment of money. Whether this requested relief is proper in equity was not addressed by appellees in the trial court or by the motions to dismiss herein. We decline to address those issues prior to their consideration and adjudication in the trial court.51
129 Appellees' sole reason for mootness is the summary judgment granted by the trial court. Generally, there are four methods for attacking a judgment.52 Taxpayer herein sought relief as a intervenor in the original suit which resulted in the judgment. Taxpayer also sought vacation of the judgment in the same District Court by another proceeding, and that request remains pending. Taxpayer's request in equity, as such relates to mootness, is similar to Threadgill, supra. In Threadgill, taxpayers sought a post-judgment order vacating that judgment in the proceeding which resulted in the judgment. The trial court denied the requested relief, and on appeal this Court reversed the trial court with directions to vacate the judgment and dismiss a petition that sought to create an unlawful obligation for the public body. Here the request for intervention relief occurred pre-judgment in the proceeding which resulted in judgment, and any relief after appellate mandate would occur postjudgment.
130 In the Tol cases we explained, and relied upon, the concept that the public body was representing all of its citizens by its conduct in presenting for adjudication a justiciable controversy to the trial court. The presentation of a justiciable controversy [128]*128included (1) the presumption that the public body's litigation conduct was in good faith, and (2) the taxpayer's duty to rebut this presumption to intervene as a gu tam inter-venor.53 Because this controversy involves (1) a judicial declaration on contested public expenditures, (2) a taxpayer alleging that the issues have not been fairly presented to the trial court and that justiciability is absent, (8) the relief sought by intervention is in equity to challenge the alleged expenditures, and (4) the inadequacy of a public body to represent a taxpayer for purposes of intervention while opposing a taxpayer's claims on the merits,54 we hold that Taxpayer's claim for equitable relief presented by a motion to intervene is not moot by the judgment rendered during the appeal. Payne v. Jones, supra; Threadgill v. Peterson, supra.
131 Taxpayer's motion relied upon 12 0.8.8upp.2003 § 2024, which provides for intervention by right, permissive intervention, and intervention by the State of Oklahoma. Taxpayer sought both intervention by right and permissive intervention.55 We have explained that § 2024(A)(2) contains four requirements for intervention: (1) the motion to intervene must be timely; (2) the interve-nor must claim a significant protectable interest relating to the property or transaction that is the subject of the action; (8) the disposition of the action may, as a practical matter, impair or impede the applicant's ability to protect its interest; and (4) the existing parties may not adequately represent the applicant's interest.56 The City argued that the motion to intervene was untimely. Federal courts have stated that timeliness for intervention is determined "in light of all of the cireumstances," and non-exclusive factors considered include the length of time since the movant knew of its interests in the case; prejudice to the existing parties; prejudice to the movant; and the existence of any unusual circumstances.57
132 TIA filed its petition for declaratory judgment on August 17th and its motion for summary judgment two months later on October 16th The responses thereto were filed October 29th and November 2nd, and four days after the last response Taxpayer filed his motion to intervene on November 6, 2007. TIA's petition for declaratory judgment included an attached photocopy of the qui tam demand incorporated by reference in the pleading. Taxpayer's motion to intervene included a gui tom claim based upon allegations that TIA, the City, and THL were not presenting a justiciable controversy to the trial court for adjudication. In addition to the pleadings, the motion to intervene [129]*129expressly relied upon the motion for summary judgment and the responses thereto. Taxpayer, as a gui tam plaintiff, had a burden of showing a lack of diligence to prosecute a justiciable controversy by TIA. In these cireumstances, Taxpayer had to wait for TIA to "show its hand" and demonstrate exactly what TIA was asking the trial court to rule upon. Any uncertainty raised by the pleadings on the issue of the diligence of TIA in presenting Taxpayer's claim to the trial court for adjudication was resolved by the TIA's motion for summary judgment and brief. Contrary to the charge of an untimely filing made by the City, Taxpayer's motion to intervene was filed with alacrity after TIA showed exactly what the "merits" of the controversy were according to its view. Taxpayer's wait and see approach before filing a combined gui tam and equitable relief intervention request was reasonable. We reject the argument that the motion to intervene was untimely.
{ 33 The objection to the intervention filed in the District Court by TIA did not address either Threadgill v. Peterson, supra, or Kellogg v. School Dist. No. 10 of Comanche County, supra, and it did not address, and therefore did not object to, the propriety of intervention based upon those opinions and the right of a taxpayer to seek equitable relief pursuant to 12 0.8. § 1897. TIA does not address this issue in its appellate brief or answer on certiorari. THL argued on appeal that Threadgill does not apply because the acts of the officials therein were unlawful, Threadgill "was based upon facts materially different than those before this court," and that in any event, Threadgill was "effectively overruled" by Tal I.58 Similarly, in the trial court the City argued that Threadgill and Kellogg involved acts by officials that were unlawful, and that since the City's acts were lawful when creating the publicly funded obligations the two cases did not apply. THL and the City thus made the question of intervention turn on the merits of Taxpayel s claim.
134 While on rare occasions an in-tervenor may be required to satisfy an evi-dentiary burden for intervention,59 intervention is usually determined on the basis of the allegations made in the motion to intervene and pleading filed by the intervenor. In 1938 we explained that intervention is based upon allegations in the intervenor's pleading when seeking intervention.60 More recently we explained that when a party "intervenes" the merits of the claim asserted by the inter-venor is not adjudicated when the party is allowed to intervene, but "once allowed to intervene, the burden is on the intervenor to prove his allegation."61 Generally, in federal courts prior to our adoption of modified federal rules for our Pleading Code, the initial [130]*130burden on the intervenor was a pleading burden, a burden to plead sufficient to satisfy federal rule 24 (our § 2024), with ordinary pleading requirements for the accompanying pleading where the nonconclusory allegations of the motion and accompanying pleading were deemed to be true when the intervention was challenged.62 The federal focus on the sufficiency of the allegations in the motion to intervene and accompanying pleading is consistent with our focus on the sufficiency of the intervenor's allegations when seeking intervention.63
1 35 Taxpayer's claim in the District Court is based upon allegations of unlawful public expenditures. Threadgill determined that taxpayers have an interest in litigation that seeks to create funding obligations on public bodies that are unlawful. Taxpayer's claim of interest herein pursuant to Threadgill and similar opinions is, generally, "an interest relating to the property or transaction which is the subject of the action and the applicant is so situated that the disposition of the action may as a practical matter impair or impede the applicant's ability to protect that interest." 12 0.$.2001 § 2024(A)(@2). Thus THL's and the City's objections using a merits-based argument were incorrect, and they should have been rejected by the District Court.
136 TIA's request for declaratory relief required it to present the merits of Taxpayer's claims that Taxpayer was seeking to present himself in the context of obtaining equitable relief. This is not merely an intervenor seeking to intervene in the same cause of action as defined by the transaction or occurrence,64 but a party seeking to intervene to present the identical claim. Taxpayer argued that a public body will not adequately represent proposed intervenor's interest in seeking equitable relief. Adequacy of representation by the existing parties is one factor considered on a motion to intervene by an intervenor. We have explained that "So long as the party has demonstrated sufficient motivation to litigate vigorously and to present all colorable contentions, a district judge does not exceed the bounds of discretion by concluding that the interests of the intervenor are adequately represented." 65 Some federal courts have indicated that a conflict of interest may be used to show a motivation to litigate less than vigorously on behalf of an intervenor,66 and that the interests need not be totally adverse before intervention is proper,67 and that a [131]*131proposed intervenor "cannot be required to look for adequate representation to one who is his [or her] opponent."68 In Threadgill v. Peterson, supra, we explained the important public policy of recognizing an equitable remedy used by taxpayers to challenge alleged illegal or unlawful public expenditures when a court is used to validate the public body's expenditure or transfer of public property.69 We conclude that Taxpayer alleged an adverse interest sufficient for § 2024(A)(2) intervention by right in TIA's proceeding seeking declaratory relief. Oklahoma Public Employees Association v. Oklahoma Department of Central Services, supra; Threadgill v. Peterson, supra; and Kellogg v. School Dist. No. 10 of Comanche County, supra.
T 37 In summary, we conclude that no gui tam claim relief could be sought on behalf of the TIA, that Taxpayer pled a claim seeking relief in equity that has been recognized by Oklahoma courts since before statehood, that the claim for equitable relief is not moot, and that the District Court erroneously denied the motion to intervene on the claim seeking equitable relief.
III Qui Tam Intervention
11 38 Whether gut tam intervention is proper requires a judicial determination that the public body has presented a justiciable controversy for the trial court to adjudicate.70 The adequacy of TIA's litigation conduct in presenting antagonistic demands of Taxpayer is not an issue as such relates to the TIA since we have concluded herein that Taxpayer has no gui tam remedy on behalf of the TIA. However, Taxpayer also pressed a gue tam claim on behalf of the City.
139 The City responded to TIA's motion and brief for summary judgment, and agreed with the legal issues briefed by TIA. TIA's motion and brief for summary judgment identified Taxpayer's claims that: (1) public trusts may not participate in retail outlets; (2) the incremental ad valorem and sales tax revenues from the Tulsa Hills Increment District could not be used to retire the bonds without violating Article 10 §§ 14, 17 and 19 of the Oklahoma Constitution; and (8) financial assistance to THL was not approved by the voters. Taxpayer alleged that the Local Development Act may not be used to create development in an area where investment, development, and economic growth would have occurred absent application of the Act, (62 0.8. § 852), and the use of that Act by the parties was improper.
T 40 Taxpayer objected to TIA, as a public trust, participating in a retail outlet. Taxpayer relied on House of Realty, Inc. v. City of Midwest City, 2004 OK 97, 109 P.3d 314, The Local Development Act, (62 O.S.2001 §§ 850-869), and 60 O.S.2001 § 178.4.71 In House of Realty, we agreed with the Attorney General that § 178.4 contains a broad prohibition on public trusts engaging in financing, constructing, and operating retail outlets, and stated that this statute "prohibits a trust engaging in an 'activity' in a retail outlet.72 In 2010 the Legislature amended § 178.4 and removed the language therein that prevented a public trust from engaging in an activity in a retail outlet.73
[132]*132{41 TIA argued that the public trust in House of Realty engaged in land acquisition, construction costs, and retail operation. TIA argued that it was providing funds for construction of specified items which it classified as infrastructure improvements and that these improvements were not of the same nature as those discussed in House of Realty. TIA concluded that the construction it was funding was thus not an activity prohibited by 60 § 178.4. The City adopted the arguments of the TIA and argued that the TIA was funding "public improvements" via funds provided to the developer. The City also argued that two sections of the Local Development Act, § 858(14)(a)(k)(o) and § 863(A) authorized TIA's conduct. The City argued that § 863(A) of the Act allowed TIA to engage in activity otherwise prohibited by 60 0.S.2001 § 178.4. Section 863(A) states:
A. With the approval of the governing body, a public entity, other than a city, town or county, may issue tax apportionment bonds or notes, other bonds or notes, or both, the proceeds of which may be used to pay project costs pursuant to the plan notwithstanding any other statutory provision to the contrary.
The City argued that if the funds provided to the developer were for the purpose of "project costs" as defined in the Local Development Act at § 853, then § 178.4 would have no effect; i.e., a public trust could violate § 178.4 and engage in retail activity if it were acting pursuant to the Local Development Act. The City pointed to the definition of "project costs" in § 853(14).74 THL made similar arguments and argued that the funds it received were for the purpose of infrastructure construction and public improvement. This issue was adequately presented to the trial court for adjudication of antagonistic demands.
142 Taxpayer argued that the financing violated Okla. Const. Art. 10 §§ 14, 17, and 19, and that a vote of the people was necessary for public-funding of the project. He argued that the funds transferred to the developer for on-site infrastructure improvements were not for a public purpose. As in City of Broken Arrow: "The issue before us on the constitutional claims is whether the City presented the legal claims of the Taxpayer [as a gui tam intervenor] to the trial court."75 TIA's brief in support of its motion for summary judgment has a discussion of Okla. Const. Art. 10 § 6C & § 19 and a lengthy discussion of the Local Development Act that need not be repeated herein. TIA, the City, and THL relied primarily on constitutional and statutory language as well as two of our opinions.76 Our review of the record shows that the combined filings of TIA, THL, and the City presented a justicia-ble controversy to the trial court as measured against Taxpayer's gui tam request for relief filed in the District Court.77 We affirm the order of the District Court to the extent that it denies intervention to Taxpayer as a gui tam plaintiff on behalf of the City.
IV. Summary
{43 Our conclusion that a justiciable controversy was presented for purposes of Tax[133]*133payer's gui tam remedy is not a decision on the merits of the issues raised by the Taxpayer, TIA, the City, or THL. The appeal presents only the narrow issue of the trial court's denial of intervention.78 Taxpayer was not allowed to intervene and his burden to prove the illegal transfer or expenditure of public funds had not yet arisen.79 We thus reach no conclusions concerning the merits of Taxpayer's claims, and we do not address defenses to those claims the defendants may possess.
44 We are not called upon in this proceeding to correct any decision of the trial court on the exact nature of a taxpayer's equitable remedy in the circumstances before us, or to explain whether specific equitable relief is proper for the present circumstances according to principles of equity. The parties did not address these issues in the trial court and we decline to address them prior to the parties presenting them for trial court adjudication. Our decision on intervention requesting equitable relief concludes only that Taxpayer met his burden to plead a claim seeking equitable relief and that he satisfied 12 0.8. § 2024.
145 We affirm the trial court's order to the extent that it denied Taxpayer's motion to intervene as a gui fam plaintiff. We reverse the trial court's order to the extent that it denied Taxpayer's motion to intervene as a taxpayer seeking equitable relief, The opinion of the Court of Civil Appeals is vacated. The matter is remanded to the District Court for further proceedings consistent with this opinion.
1 46 ALL JUSTICES CONCUR.