Opinion
PALMER, J.
This appeal marks the parties’ third visit to this court in connection with litigation spanning three decades and arising out of a claim by the plaintiff, Ludmil A. Chotkowski, that the defendant, the state of Connecticut, improperly reduced his salary while he was employed at the state Veterans’ Home and Hospital over twenty years ago. The principal issues raised by this appeal are: (1) whether a special act of the legislature; Spec. Acts 1991, No. 91-8;1 authorizing the plaintiff to [249]*249present a claim to the claims commissioner requesting permission to bring an action against the state after the expiration of the limitation period applicable to his claim, constitutes an “exclusive public emolument” prohibited by article first, § 1, of the Connecticut constitution;2 and (2) if not, whether the trial court properly rejected the plaintiffs claims for breach of express contract, breach of implied contract and promissory estop-pel. The plaintiff commenced this action after the claims commissioner, acting pursuant to the authority conferred upon him by No. 91-8 of the 1991 Special Acts (S.A. 91-8), granted the plaintiff permission to sue the state. At trial, the state claimed that S.A. 91-8 violates article first, § 1, of the state constitution and, consequently, that the claims commissioner lacked jurisdiction to entertain the plaintiffs request for permission to sue the state. The state further maintained that even if S.A. 91-8 satisfies constitutional requirements, the plaintiff had failed to establish that he was entitled to relief under any of his claims. The trial court rejected the state’s constitutional argument, but rendered judgment for the state on the ground that the plaintiff had failed to prove his claims. The plaintiff appealed from [250]*250the judgment of the trial court to the Appellate Court, and we transferred the appeal to this court pursuant to Practice Book § 4023 and General Statutes § 51-199 (c). We affirm the judgment of the trial court.
The following facts and procedural history are relevant to this appeal. In November, 1969, the plaintiff, a physician, left his private medical practice to accept an appointment as a “special assistant” at the state Veterans’ Home and Hospital in Rocky Hill. In February, 1975, the position of special assistant was eliminated, and the plaintiff was reclassified as a “professional specialist” with no reduction in pay. The plaintiff then received notice of his proposed reclassification to “chief of medicine.” Through correspondence with various state administrators, the plaintiff protested his reclassification and corresponding salary reduction. On May 20, 1975, he forwarded a letter to the state department of personnel and administration requesting the “opportunity of appealing this decision before it should become final.” The commissioner of personnel and administration, Frederic Rossomando, responded by letter dated June 3,1975 (Rossomando letter), in which, contrary to applicable law, he stated: “I am advised that there is no existing statute or regulation which would permit such an appeal, either to me or any other appropriate body.” Thereafter, on June 6, 1975, the plaintiff was reclassified to the position of “chief of medicine,” and his salary was reduced by $303.64 biweekly.
On April 8, 1976, nearly one year later, the plaintiffs employment was terminated as a result of his continued conflicts with administration officials over his salary reduction.3 The plaintiff appealed the termination to the state personnel appeal board (board), which dismissed [251]*251the appeal, concluding that the plaintiff was not entitled to review of his claims because he was not a “permanent employee holding a position in the classified service” within the meaning of General Statutes (Rev. to 1975) § 5-202 (a).4 The plaintiffs administrative appeal of the board’s decision was sustained by the trial court, Pickett, J., on the ground that the plaintiff was a permanent employee in the classified state service for purposes of § 5-202 (a). The board appealed to this court, and we affirmed the judgment of the trial court. Chotkowski v. Connecticut Personnel Appeal Board, 176 Conn. 1, 404 A.2d 868 (1978). The parties eventually agreed to a settlement of the plaintiffs employment termination claim.
After settling his employment termination claim, the plaintiff filed a notice of claim with the claims commissioner under General Statutes § 4-1475 requesting permission to sue the state for lost wages based upon the allegedly improper reclassification and salary reduction. The claims commissioner rejected the plaintiffs claim, concluding that it was barred by the one year [252]*252limitation for presenting claims against the state prescribed by General Statutes (Rev. to 1979) § 4-148 (a).6
Thereafter, the legislature, at the plaintiffs urging, passed No. 85-24 of the 1985 Special Acts (S.A. 85-24),7 which authorized the plaintiff to prosecute his claim against the state despite his failure to comply with the requirements of § 4-148 (a). The plaintiff then renewed his claim to the claims commissioner, who granted the plaintiff permission to sue the state in accordance with General Statutes (Rev. to 1985) § 4-160 (a).8
[253]*253The plaintiff subsequently commenced an action against the state alleging breach of contract and promissory estoppel. The trial court, O'Neill, -/., granted the state’s motion for summary judgment on the ground that the plaintiff, as a permanent employee in the classified state service, enjoyed only statutory, and not contractual, employment rights. The plaintiff appealed to this court and we held that S.A. 85-24 constituted an “exclusive public emolument” prohibited by article first, § 1, of the state constitution. Accordingly, we remanded the case to the trial court with direction to dismiss the plaintiffs action for lack of jurisdiction.9 Chotkowski v. State, 213 Conn. 13, 566 A.2d 419 (1989) (Chotkowski II).
The legislature then enacted No. 90-284 of the 1990 Public Acts (P.A. 90-284), now codified at § 4-148 (b),10 which provides that the legislature, by special act, may excuse a claimant’s failure to file a timely notice with the claims commissioner provided that the legislature “deems such authorization to be just and equitable and makes an express finding that such authorization is supported by compelling equitable circumstances and would serve a public purpose.” Section 4-148 (b) also purports to ensure that the legislature’s “finding shall not be subject to review by the superior court.”11
[254]*254Acting under the aegis of § 4-148 (b), the legislature, again at the request of the plaintiff, enacted S.A. 91-8, which, like S.A. 85-24, authorizes the plaintiff to present his claim to the claims commissioner notwithstanding his lack of compliance with § 4-148 (a). Unlike S.A. 85-24, however, S.A. 91-8 is predicated upon an express legislative finding that the plaintiff “failed to timely file a notice of a claim against the state with the claims commissioner because he was misinformed by a state official and was misled by such official into believing that he had no right of redress against the state for the damages he allegedly suffered,” and, further, “that there are compelling equitable circumstances to support such authorization and that such authorization would serve a public purpose.” See footnote 1. The plaintiff, upon passage of S.A. 91-8, renewed his claim with the claims commissioner, who again granted him permission to bring an action against the state.
The plaintiff then commenced this suit alleging breach of express contract, breach of implied contract and promissory estoppel.12 The state moved to dismiss
[255]*255the action for lack of jurisdiction on the ground that S.A. 91-8 violates article first, § 1, of the state constitution. The trial court, Stengel, J., denied the state’s motion. The state thereafter filed a motion for summary judgment in which it renewed its constitutional challenge to S.A. 91-8 and, in addition, claimed that (1) the plaintiffs request for permission to sue the state was barred by § 4-148 (c), and (2) the plaintiff had failed to state a legally sufficient cause of action because his employment rights were statutory, rather than contractual, in nature. The trial court, Fineberg, J., denied the state’s motion on the ground that there were disputed factual issues material to the plaintiffs claims; see Practice Book § 378 et seq.; see also Doty v. Mucci, 238 Conn. 800, 805, 679 A.2d 945 (1996); and a trial to the court ensued. At the conclusion of the trial, the court, Fineberg, J., rendered judgment for the state, concluding that the plaintiff had failed to establish that his employment with the state gave rise to any contractual rights and, further, that he had failed to prove the elements of his promissory estoppel claim.13
On appeal, the plaintiff claims that the trial court improperly determined that he had failed to establish [256]*256that he was entitled to relief under each of his claims.14 The state contends that the trial court improperly rejected its claim that S.A. 91-8 violates article first, § 1, of the state constitution and that the claims commissioner did not have jurisdiction to entertain the plaintiffs claim requesting permission to sue the state. The state further contends that even if S.A. 91-8 is constitutional, the trial court lacked jurisdiction over the plaintiffs action because the claim that he filed with the claims commissioner was barred by both General Statutes § 4-14215 and General Statutes § 4-148 (c).16 Finally, the state maintains that even if the claims commissioner had jurisdiction to consider the plaintiffs request for permission to bring this action, the trial court properly concluded that the plaintiff had failed to establish that he was entitled to relief under any of his claims.17 [257]*257Because we agree with the trial court’s conclusions, we affirm the judgment of the trial court.
I
Before turning to the plaintiffs contention that the trial court improperly rejected his claims, we must first consider the state’s claim that the trial court lacked jurisdiction over the plaintiffs action. See Cannata v. Dept. of Environmental Protection, 239 Conn. 124, 134, 680 A.2d 1329 (1996); Figueroa v. C & S Ball Bearing, 237 Conn. 1, 4, 675 A.2d 845 (1996). The state’s principal contention is that S.A. 91-8 violates the prohibition against “exclusive public emoluments or privileges from the community” contained in article first, § 1, of the Connecticut constitution and, consequently, that the claims commissioner lacked authority to entertain the plaintiffs request for permission to sue the state. The trial court concluded that S.A. 91-8 serves a valid public purpose and, therefore, that it does not run afoul of article first, § 1. We agree with the trial court.
To prevail under article first, § 1, of our constitution, the state must demonstrate that “the sole objective of the General Assembly is to grant personal gain or advantage to an individual.” State ex rel. Higgins v. Civil Service Commission, 139 Conn. 102, 106, 90 A.2d 862 (1952). If, however, an enactment serves a legitimate public purpose, then it will withstand a challenge under article first, § 1. Serrano v. Aetna Ins. Co., 233 Conn. 437, 458-59, 664 A.2d 279 (1995); Tough v. Ives, 162 Conn. 274, 292, 294 A.2d 67 (1972). Moreover, we conduct our review of S.A. 91-8 mindful that “legislative enactments carry with them a strong presumption of constitutionality, and that a party challenging the con[258]*258stitutionality of a validly enacted statute bears the heavy burden of proving the statute unconstitutional beyond a reasonable doubt.” Beccia v. Waterbury, 192 Conn. 127, 133, 470 A.2d 1202 (1984); see also Farad v. Connecticut Light & Power Co., 211 Conn. 166, 168, 558 A.2d 234 (1989).
The plaintiff claims that the trial court lacked authority to consider the propriety of the legislative finding that S.A. 91-8 serves a public purpose because such review is barred by § 4-148 (b), which provides in pertinent part that “[sjuch finding shall not be subject to review by the superior court.” See footnote 10. The plaintiff maintains that this legislative prohibition against judicial review is valid because § 4-148 (b) deals with the doctrine of sovereign immunity, and “[i]t is a matter for the legislature, not this court, to determine when our state’s sovereign immunity should be waived.” Struckman v. Burns, 205 Conn. 542, 558, 534 A.2d 888 (1987). We disagree. Because an enactment must serve a valid public purpose in order to avoid the prohibition against the granting of “exclusive public emoluments and privileges” contained in article first, § 1, of the state constitution, the determination of whether an enactment serves such a purpose is necessarily one of constitutional magnitude. It is the court’s duty to ensure that legislative action falls within constitutional boundaries; Marbury v. Madison, 5 U.S. (1 Cranch) 137, 177-78, 2 L. Ed. 60 (1803); Szarwak v. Warden, 167 Conn. 10, 27, 355 A.2d 49 (1974); even if that action involves a waiver of the immunity from suit enjoyed by the state under the common law. Consequently, the legislature cannot “by mere fiat or finding, make ‘public’ a truly ‘private’ purpose . . . .Its findings and statements about what is or is not ‘public’ cannot be binding upon the court. Lyman v. Adorno, [133 Conn. 511, 517, 52 A.2d 702 (1947)].” Wilson v. Connecticut Product Development Corp., 167 Conn. 111, 116 n.2, [259]*259355 A.2d 72 (1974). Accordingly, § 4-148 (b) would be constitutionally infirm to the extent that it were construed to shield from judicial review a legislative determination that its enactment meets the requirements of article first, § 1, of our state constitution.
The scope of our review as to whether an enactment serves a public purpose is limited. “[Wjhat constitutes a public purpose is primarily a question for the legislature, and its determination should not be reversed by the court unless it is manifestly and palpably incorrect.” Barnes v. New Haven, 140 Conn. 8, 15, 98 A.2d 523 (1953); see also Wilson v. Connecticut Product Development Corp., supra, 167 Conn. 115-16; Roan v. Connecticut Industrial Building Commission, 150 Conn. 333, 345, 189 A.2d 399 (1963). “[W]e are not to assess [the constitutionality of an act] in the light of what we think of the wisdom and discernment of the law-making body in the particular instance. Rather we are bound to approach the question from the standpoint of upholding the legislation as a valid enactment unless there is no reasonable ground upon which it can be sustained.” Roan v. Connecticut Industrial Building Commission, supra, 338; see also Warner v. Gabb, 139 Conn. 310, 313, 93 A.2d 487 (1952). Thus, “if there be the least possibility that making the gift will be promotive in any degree of the public welfare, it becomes a question of policy and not of natural justice; and the determination of the legislature is conclusive.” Lyman v. Adorno, supra, 133 Conn. 524. In other words, if we can discern “any conceivable justification for [the] challenged legislation from the public viewpoint”; Merly v. State, 211 Conn. 199, 205, 558 A.2d 977 (1989); we are bound to uphold it against a constitutional challenge predicated on article first, § 1.
Although “[w]e have taken abroad view of the legislative goals that may constitute a ‘public puipose’ ”; Beccia v. Waterbury, supra, 192 Conn. 134; “[b]ecause the [260]*260elements of a public purpose vary as much as the circumstance in which the term is appropriate, each case must be determined on its own peculiar facts.” Tough v. Ives, supra, 162 Conn. 292. In general, however, we have found “that an act serves a public purpose under article first, § 1, when it promote[s] the welfare of the state ... or when the principal reason for the appropriation is to benefit the public. ...” (Citations omitted; internal quotation marks omitted.) Beccia v. Waterbury, supra, 134; Wilson v. Connecticut Product Development Corp., supra, 167 Conn. 117. Furthermore, an enactment will be deemed to serve a valid public purpose, even though it confers a direct benefit upon a particular individual, if it remedies an injustice done to that individual for which the state itself bears responsibility. Sanger v. Bridgeport, 124 Conn. 183, 189, 198 A. 746 (1938); see also Chotkowski II, supra, 213 Conn. 18; Merly v. State, supra, 211 Conn. 213-14; Vecchio v. Sewer Authority, 176 Conn. 497, 506-507, 408 A.2d 254 (1979); Hillier v. East Hartford, 167 Conn. 100, 108-109, 355 A.2d 1 (1974). In such circumstances, the benefit conferred upon a private party by the legislature may be viewed as incidental to the overarching public interest that is served in remedying an injustice caused by the state.18
[261]*261In this case, the legislature, acting on the basis of undisputed testimony detailing the circumstances surrounding the plaintiffs failure to file a claim within the period prescribed by § 4-148 (a); see Conn. Joint Standing Committee Hearings, Judiciary, Pt. 2, 1991 Sess., pp. 610-14; expressly found that the plaintiff had failed to comply with § 4-148 (a) “because he was misinformed by a state official and was misled by such official into believing that he had no right of redress against the state for the damages he allegedly suffered.” S.A. 91-8; see footnote 1. The legislature further concluded that the plaintiffs request for special authorization to file a late claim with the claims commissioner was supported by “compelling equitable circumstances” and that “such authorization would serve a public purpose.” S.A. 91-8; see footnote 1. These conclusions are supported by the testimony presented to the legislature and, as the trial court determined, by the evidence adduced at trial. We cannot conclude, therefore, that the legislative findings and conclusions are manifestly and palpably incorrect.19
As noted by the plaintiff, the circumstances of this case are similar to those of Sanger v. Bridgeport, supra, 124 Conn. 183, in which we upheld the constitutionality [262]*262of a special act validating a statutorily defective notice to the city of Bridgeport alleging injuries suffered by the plaintiff due to a defective sidewalk. In Sanger, the plaintiff had “alleged that [the defective notice] was prepared by an assistant to the city clerk of Bridgeport, upon whom the plaintiff relied for its preparation and to whom was given all essential facts which were necessary for a notice sufficient to the requirements of the statute . . . .” Id., 185. In concluding that the challenged legislation did not contravene constitutional requirements, we recognized that there exist “strong equitable grounds for legislative interference” when a government official has caused a procedural default that adversely affects the substantive rights of the party seeking legislative intervention. Id., 189; see also Chot-kowski II, supra, 213 Conn. 18. Here, as in Sanger, the challenged special act seeks to remedy an inequity that the legislature rationally concluded had resulted from the plaintiffs reasonable reliance on the misleading conduct of a state official.20
The state contends that Chotkowski II disposes of the plaintiffs claim that a valid public purpose is served by allowing the plaintiff to prosecute his claim against [263]*263the state. The state, however, miscontraes the scope of our decision in Chotkowski II, wherein the plaintiff disputed the state’s constitutional challenge to S.A. 85-24 solely on the ground that equity required the enactment of such remedial legislation in light of the promise of permanent employment allegedly made to him by the state. Thus, as we expressly noted in Chotkowski II, “[the plaintiff] does not even claim . . . that the state caused the delay in presenting his claim to the claims commissioner .... The only consideration he advances is that the legislature may have intended to recognize an honorary obligation so that substantial justice could be realized. . . . The honorary obligation relied upon by the plaintiff, however, is based wholly upon the asserted merit of his cause of action for breach of contract and does not implicate the delay in filing his claim with the claims commissioner.” (Citations omitted; internal quotation marks omitted.) Chotkowski II, supra, 213 Conn. 18.
Similarly, nowhere does the legislative history of S.A. 85-24 indicate that the legislature was apprised of the Rossomando letter or of the plaintiffs failure to file a claim in a timely manner in reliance on the representations contained therein. Indeed, because the testimony in support of S.A. 85-24 focused solely upon the alleged merit of the plaintiffs claim against the state; see Conn. Joint Standing Committee Hearings, Judiciary, Pt. 4, 1985 Sess., pp. 1090-92, 1249; we must presume that the enactment of S.A. 85-24 was predicated on that information. Thus, our conclusion in Chotkowski II that, S.A. 85-24 did not serve a public purpose does not preclude a determination that S.A. 91-8 satisfies that constitutional requirement.
We conclude, therefore, that because S.A. 91-8 serves a legitimate public purpose, it does not violate article first, § 1, of the Connecticut constitution. Accordingly, [264]*264the trial court properly rejected the state’s constitutional challenge to S.A. 91-8.
II
We next consider the state’s argument that the plaintiffs claim requesting permission to sue the state was barred by § 4-142. See footnote 15. We are not persuaded by this argument.
The claims commissioner has authority to hear all claims against the state except those expressly enumerated in § 4-142. The state first contends that the plaintiffs claim was barred by § 4-142 (1), which excepts from the claims commissioner’s jurisdiction “[cjlaims for the periodic payment of disability, pension, retirement or other employment benefits.” The state further maintains that the plaintiff was entitled to a review of his salary reduction by the personnel appeal board under § 5-20221 and, consequently, that consideration of his claim by the claims commissioner was precluded by § 4-142 (3), which bars the claims commissioner’s review of “claims for which an administrative hearing procedure otherwise is established by law.”
The plaintiffs claim that his wages were improperly reduced by the state when he was reclassified to the position of chief of medicine does not fall into either of these two categories limiting the claims commissioner’s jurisdiction. With respect to § 4-142 (1), the plaintiff does not claim that he was improperly deprived of a periodic payment of the kind enumerated therein; instead, he seeks lump sum damages for his lost wages. Furthermore, because the plaintiffs action against the state is predicated solely on principles of contract law, it does not appear that the board was authorized under § 5-202 to afford the plaintiff the contract remedy that [265]*265he seeks.22 We are not persuaded, therefore, that the plaintiff had an available administrative remedy within the meaning of § 4-142 (3). Accordingly, we agree with the trial court that the plaintiffs claim requesting permission to bring this action against the state was not barred by § 4-142.
Ill
The state also claims that the plaintiffs request for permission to sue the state was foreclosed by § 4-148 (c), which provides in pertinent part that “no claim once considered by the claims commissioner, by the general assembly or in a judicial proceeding shall again be presented against the state in any manner.” See footnote 16. We disagree.
As the state maintains, the principle underlying § 4-148 (c) is that of res judicata. That common law doctrine, also known as “claim preclusion, [provides that] a former judgment on a claim, if rendered on the merits, is an absolute bar to a subsequent action on the same claim.” (Internal quotation marks omitted.) Delahunty v. Massachusetts Mutual Life Ins. Co., 236 Conn. 582, 589, 674 A.2d 1290 (1996). Although the state concedes that our judgment in Chotkowski II ordering the dismissal of the plaintiffs action did not entail a consideration of the merits of the plaintiffs claim, the state maintains that § 4-148 (c) imposes a broader prohibition against successive claims than does the doctrine of res judicata. Under the interpretation urged by the state, § 4-148 (c) bars a claim against the state if that claim has already been reviewed by the claims commissioner, the legislature or the judiciary whether or not the reviewing body considered the merits of the claim.23
[266]*266We reject this interpretation for two principal reasons. First, in the absence of any persuasive reason to the contrary, we are not inclined to construe § 4-148 (c) more narrowly than the common law doctrine upon which it is concededly based.24 Second, under the state’s construction of § 4-148 (c), a claimant whose request for permission to sue the state has been rejected as untimely by the claims commissioner would be precluded from seeking a special act of the legislature waiving the applicable limitation period even though that claimant could have established that the filing delay had been caused by the state.25 We are not persuaded that the legislature intended such a result. See, e.g., State v. Anonymous, 237 Conn. 501, 514-15, 680 A.2d 956 (1996) (law favors sensible and rational construction of statute rather than one leading to difficult and possibly bizarre consequences). Accordingly, we reject the state’s argument that § 4-148 (c) bars the claims commissioner from considering the plaintiffs claim.
IV
We now turn to the plaintiffs claim that the trial court improperly rendered judgment for the state on the ground that the plaintiff, as a classified state employee, enjoyed only statutory, and not contractual, employment rights. We agree with the trial court’s conclusion.
[267]*267We have previously concluded that state employees do not have contractual employment rights absent a clear and unambiguous expression of legislative intent to the contrary. Pineman v. Oechslin, 195 Conn. 405, 416, 488 A.2d 803 (1985); see also Kinney v. State, 213 Conn. 54, 65 n.17, 566 A.2d 670 (1989). If this were not the case, “the state would be powerless to reduce the pay or shorten the tenure of any state employee without posing a possible contract clause violation. We do not believe that such a heavy obligation may be imposed upon the state unless the legislature clearly evidences an intent to assume it.” Pineman v. Oechslin, supra, 416; see also National R. Passenger Corp. v. Atchison, Topeka & Santa Fe Railway Co., 470 U.S. 451, 465-66, 105 S. Ct. 1441, 84 L. Ed. 2d 432 (1985) (absent clear indication by legislature to contrary, presumption is that legislation does not create private contractual rights but merely sets policy to be followed until legislature ordains otherwise). Thus, state employees serve by appointment, and “their entitlement to pay and other benefits ‘must be determined by reference to the statutes and regulations governing [compensation], rather than to ordinary contract principles.’ ” Kizas v. Webster, 707 F.2d 524, 535 (D.C. Cir. 1983), cert. denied, 464 U.S. 1042, 104 S. Ct. 709, 79 L. Ed. 2d 173 (1984), quoting United States v. Larionoff, 431 U.S. 864, 869, 97 S. Ct. 2150, 53 L. Ed. 2d 48 (1977). Accordingly, the plaintiff can prevail on his contract claims only if he can establish that the legislature intended to bind the state contractually under the statutory scheme pursuant to which he was appointed. See Pineman v. Oechslin, supra, 416; see also Dodge v. Board of Education, 302 U.S. 74, 78, 58 S. Ct. 98, 82 L. Ed. 57 (1937).
The plaintiff points to nothing in the statutes applicable to classified state employees; see General Statutes (Rev. to 1975) §§ 5-200 through 5-208; or elsewhere in our laws and regulations, to support his claim of con[268]*268tractual entitlement Because his express and implied contract26 claims are predicated on the existence of rights that he does not possess, the trial court properly concluded that the plaintiff is not entitled to relief on those counts.
The trial court also properly determined that the plaintiff could not prevail on his claim of promissory estoppel. “Under our well-established law, any claim of estoppel is predicated on proof of two essential elements: the party against whom estoppel is claimed must do or say something calculated or intended to induce another party to believe that certain facts exist and to act on that belief; and the other party must change its position in reliance on those facts, thereby incurring some injury. . . . It is fundamental that a person who claims an estoppel must show that he has exercised due diligence to know the truth, and that he not only did not know the true state of things but also lacked any reasonably available means of acquiring knowledge.” (Citations omitted; internal quotation marks omitted.) Connecticut National Bank v. Voog, 233 Conn. 352, 366, 659 A.2d 172 (1995); see also D’Ulisse-Cupo v. Board of Directors of Notre Dame High School, 202 Conn. 206, 213, 520 A.2d 217 (1987). “In addition, estoppel against a public agency is limited and may be invoked: (1) only with great caution; (2) only when the action in question has been induced by an agent having authority in such [269]*269matters; and (3) only when special circumstances make it highly inequitable or oppressive not to estop the agency.” Kimberly-Clark Corp. v. Dubno, 204 Conn. 137, 148, 527 A.2d 679 (1987). Finally, a claim for promissory estoppel will not lie against the state unless “the party claiming estoppel would be subjected to substantial loss if the public agency were permitted to negate the acts of its agents.” Id.
The evidence fully supports the trial court’s determination that the plaintiff failed to prove his claim of estoppel. The only statement made by state officials to the plaintiff was that “he would be paid $35,000.00 per year, and . . . that said rate of pay would be subject to future increases.” As the trial court found, the facts alleged and proven by the plaintiff were “neither sufficiently promissory nor sufficiently definite” to support the plaintiffs claim. See D’Ulisse-Cupo v. Board of Directors of Notre Dame High School, supra, 202 Conn. 214. Moreover, the plaintiff offered no proof that the state officials were empowered to bind the state; see, e.g., Kimberly-Clark Corp. v. Dubno, supra, 204 Conn. 148; or that the plaintiff exercised due diligence in seeking to ascertain whether they were authorized to do so. See Connecticut National Bank v. Voog, supra, 233 Conn. 366. Because the plaintiff failed to establish the essential elements of his claim of promissory estoppel, the trial court properly rendered judgment for the state with respect to that count.
The plaintiff contends that his rights vis-a-vis the state are not limited to the statutory rights that he possessed in 1975 because, he claims, § 4-160 places the state in the position of a private person and, therefore, allows any claims that could be brought against a private person to be brought against the state, including claims for breach of an employment contract. It is true that § 4-160 provides for the waiver of the state’s sovereign immunity, thus making the state’s rights and liability [270]*270“coextensive with and equal to those of a private person in like circumstances.” Sullivan v. State, 189 Conn. 550, 557, 457 A.2d 304 (1983). The sole purpose of § 4-160, however, is to remove the bar of sovereign immunity when the claims commissioner determines that it would be “just and equitable” to permit a claimant to seek redress against the state. See footnote 8. Contrary to the plaintiffs claim, there is no indication that the legislature, in empowering the claims commissioner to waive the state’s immunity from suit, intended to enhance or otherwise to modify a plaintiffs substantive rights. Consequently, § 4-160 cannot be construed to alter the terms and conditions of the plaintiffs state employment or otherwise affect the fundamental nature of the parties’ relationship.27
The judgment is affirmed.
In this opinion KATZ, MCDONALD and PETERS, JS., concurred.