
575 N.W.2d 31 (1997)
226 Mich. App. 558
Maria E. DRIVER, Plaintiff-Appellant,
v.
William HANLEY and Julia Hanley, Defendants-Appellees.
Docket No. 193047.
Court of Appeals of Michigan.
Submitted June 11, 1997, at Grand Rapids.
Decided November 25, 1997, at 9:10 a.m.
Released for Publication March 10, 1998.
*33 Cunningham Davison Roges & Alward by William M. Davison, Traverse City, for Plaintiff-Appellant. Michael E. Hall, Traverse City, for Defendants-Appellees.
Before REILLY, P.J., and HOOD and MURPHY, JJ.


*32 AFTER REMAND
PER CURIAM.
Plaintiff appeals as of right from an order granting defendants' motion for summary disposition of plaintiff's claim under § 2 of the Whistleblowers' Protection Act (WPA), M.C.L. § 15.362; M.S.A. § 17.428(2). Plaintiff also contests the circuit court's subsequent order denying plaintiff's motion for reinstatement of a prior district court judgment. We affirm the circuit court's order granting defendants' motion for summary disposition. We reverse, in part, the circuit court's order denying plaintiff's motion seeking reinstatement of the district court judgment.
This case is before this Court for the second time. In 1985, plaintiff was discharged from her employment with defendants. The facts underlying plaintiff's discharge were set forth in this Court's first opinion. See Driver v. Hanley, 207 Mich.App. 13, 14-15, 523 N.W.2d 815 (1994). As noted in that opinion, plaintiff filed a complaint in the circuit court against defendants alleging (1) a violation of the WPA, (2) a violation of the public policy against retaliatory discharge, and (3) a breach of her employment contract. Because the parties received a mediation evaluation below the jurisdictional limit, the case was removed to the district court, where a jury, in a special verdict, found in favor of plaintiff on each count and awarded $24,800 in damages. On appeal, the circuit court (1) affirmed the district court verdict on plaintiff's WPA count, (2) reversed the verdict on her public policy count on the ground that plaintiff failed to exhaust her administrative remedies,[1] and (3) reversed the verdict on her breach of contract count on the ground that it was preempted by the WPA. Defendants then appealed to this Court on leave granted, and plaintiff cross appealed. Defendants argued that the district court lacked subject-matter jurisdiction over plaintiff's WPA claim on the ground that exclusive jurisdiction was within the circuit court. This Court agreed and reversed the circuit court's ruling with respect to plaintiff's WPA claim. Driver, supra at 16-18, 523 N.W.2d 815. In her cross appeal, plaintiff argued that the circuit court erred in reversing the verdict on her breach of contract count. This Court disagreed and affirmed the circuit court verdict with respect to plaintiff's breach of contract count, holding that the WPA provided her exclusive remedy. Id. at 18, 523 N.W.2d 815.
*34 After remand from this Court, plaintiff was left with only a WPA claim pending in the circuit court. Defendants moved for summary disposition pursuant to MCR 2.116(C)(8) and (C)(10), arguing that plaintiff could not sustain a successful claim under the WPA under the facts as alleged and developed. In particular, defendants argued that plaintiff's alleged report to the United States Department of Labor (USDL) was insufficient to support plaintiff's claim, because the USDL did not constitute a "public body" within the meaning of the WPA. According to defendants, the WPA did not offer protection to employees discharged for reporting to federal agencies. The circuit court agreed and granted defendants' motion for summary disposition. Plaintiff then moved for reinstatement of the original district court judgment, arguing that the dismissal of her other two claims had been predicated solely on the existence of a valid WPA claim against defendants. The circuit court denied plaintiff's motion, reasoning that the WPA precluded plaintiff's public policy and breach of contract claims despite being inapplicable to plaintiff's case.
Plaintiff first contends that the circuit court erred in dismissing her claim under the WPA. A trial court's determination regarding a motion for summary disposition is reviewed de novo. Atkinson v. Detroit, 222 Mich.App. 7, 9, 564 N.W.2d 473 (1997). Here, the circuit court did not specify which subsection of MCR 2.116(C) it was relying on when it granted defendants' motion for summary disposition. However, because it relied on matters outside the pleadings, we will construe the motion as having been granted pursuant to MCR 2.116(C)(10). Osman v. Summer Green Lawn Care, Inc., 209 Mich. App. 703, 705, 532 N.W.2d 186 (1995). A motion for summary disposition may be granted pursuant to MCR 2.116(C)(10) when there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law. Atkinson, supra at 9, 564 N.W.2d 473. The moving party is entitled to judgment as a matter of law if the claim suffers a deficiency that cannot be overcome. Id.
Plaintiff does not argue that the circuit court erred substantively in dismissing her WPA claim on the ground that the USDL was not a "public body."[2] Accordingly, we will not address the issue whether an agency of the federal government constitutes a "public body" for purposes of the WPA. Radtke v. Everett, 442 Mich. 368, 397-398, & n. 48, 501 N.W.2d 155 (1993). Instead, plaintiff argues only that defendants should have been estopped from asserting that the WPA was inapplicable to plaintiff's case. In Michigan, the doctrine of judicial estoppel prohibits a party who has successfully and unequivocally asserted a position in a prior proceeding from asserting a wholly inconsistent position in a subsequent proceeding. Paschke v. Retool Industries, 445 Mich. 502, 509-510, 519 N.W.2d 441 (1994). The fact that the prior and subsequent proceedings in this case occurred within the same litigation is not a bar to the application of the doctrine. See Detroit Edison Co. v. Public Service Comm., 221 Mich.App. 370, 382, 562 N.W.2d 224 (1997).
Here, defendants successfully argued to the circuit court (on appeal from the district court) and to this Court that the WPA provided plaintiff's exclusive remedy. Then, on remand to the circuit court, defendants argued that the WPA was inapplicable to the specific facts of plaintiff's case. Plaintiff contends that defendants' "new" position, allegedly taken for the first time on remand, was wholly inconsistent with defendants' prior position. We disagree. Contrary to plaintiff's assertion, defendants' position on remand regarding the applicability of the WPA to the specific facts of plaintiff's case did not conflict with their prior arguments and was not a new position. Defendants first raised both arguments in their original (and ultimately unsuccessful) motions for summary disposition filed in 1986.[3] Moreover, at no time did *35 defendants ever assert, unequivocally, that the WPA was applicable to the specific facts of plaintiff's case. After the initial district court judgment, defendants' arguments did not address the applicability of the WPA to the specific facts of plaintiff's case. Instead, defendants merely argued that, because plaintiff had alleged a violation of the WPA, she could not, as a matter of law, allege a cumulative breach of contract claim. Finally, we note that plaintiff failed to raise the issue of judicial estoppel before the circuit court and therefore failed to preserve the issue for appellate review. Chilingirian v. City of Fraser, 194 Mich.App. 65, 70-71, 486 N.W.2d 347 (1992), remanded 442 Mich. 874, 500 N.W.2d 470 (1993), on remand 200 Mich.App. 198, 504 N.W.2d 1 (1993). For these reasons, we hold that the circuit court did not err in allowing defendants to argue that the WPA was inapplicable to the specific facts of plaintiff's case. See Paschke, supra at 509-510, 519 N.W.2d 441.
Plaintiff next argues, in the alternative, that because the circuit court dismissed her WPA claim, which had been deemed her "exclusive remedy," it should have reinstated the judgment of the district court with respect to her public policy and breach of contract claims. A trial court on remand possesses the authority to take any action that is consistent with the opinion of the appellate court. VanderWall v. Midkiff, 186 Mich.App. 191, 196, 463 N.W.2d 219 (1990). In this case, it is apparent from the record that when plaintiff requested reinstatement of the district court judgment, she was in fact requesting relief from the original circuit court order dismissing the district court's favorable judgment on her public policy and breach of contract claims.[4] Under MCR 2.612(C)(1)(f), relief from judgment may be granted for "any reason justifying relief from the operation of the judgment." Huber v. Frankenmuth Mut. Ins. Co., 160 Mich.App. 568, 575-576, 408 N.W.2d 505 (1987). A trial court's decision to grant such relief is discretionary and will not be disturbed absent an abuse of discretion. Id. at 576, 408 N.W.2d 505.
The law of the case doctrine provides that a ruling by an appellate court with regard to a particular issue binds the appellate court and all lower tribunals with respect to that issue. Reeves v. Cincinnati, Inc. (After Remand), 208 Mich.App. 556, 559, 528 N.W.2d 787 (1995). Thus, a question of law decided by an appellate court will not be decided differently on remand or in a subsequent appeal in the same case. Id. This rule applies without regard to the correctness of the prior determination. Id. However, the law of the case doctrine controls only if the facts have remained materially the same. CAF Investment Co. v. Saginaw Twp., 410 Mich. 428, 454, 302 N.W.2d 164 (1981).
In deciding the first appeal in this case, this Court relied on the "well established" rule that "the WPA provides the exclusive remedy for an employee who has been discharged wrongfully from employment for reporting an employer's violation of the law." Driver, supra at 18, 523 N.W.2d 815. We then held that, because plaintiff's breach of contract claim "was based solely on the fact that she reported defendants' violations of the law," the remedy provided by the WPA was exclusive. Id. This Court's holding was expressly limited to the facts of the case, and in reciting the facts, we incorrectly stated that plaintiff had "filed a complaint with the Michigan Department of Labor, Wage and Hour Division." Id. at 15, 18, 523 N.W.2d 815. On remand, the circuit court dismissed plaintiff's WPA claim because plaintiff's report was made to the USDL, a federal agency. Both parties agree that plaintiff's report was made to the federal agency rather than a state agency. Accordingly, because the key fact upon which the circuit court relied to dismiss plaintiff's "exclusive remedy" was not among the facts apparently relied on by this Court, the law of the case doctrine was not applicable on remand and does not now bind this Court on the issue. CAF Investment, supra at 454, 302 N.W.2d 164.
*36 As a general rule, remedies provided by a statute for the violation of a right having no common-law counterpart are exclusive rather than cumulative. Dudewicz v. Norris Schmid, Inc., 443 Mich. 68, 78, 503 N.W.2d 645 (1993), citing Pompey v. General Motors Corp., 385 Mich. 537, 552-553, 189 N.W.2d 243 (1971). The WPA is such a statute. Dudewicz, supra at 79, 503 N.W.2d 645; Covell v. Spengler, 141 Mich.App. 76, 82-84, 366 N.W.2d 76 (1985). The Michigan Supreme Court, in Dudewicz, supra at 80, 503 N.W.2d 645, held that because the WPA provided relief, the plaintiff's cumulative public policy claim was not sustainable. The Court explained that a public policy claim is sustainable "only where there is not an applicable statutory prohibition against discharge in retaliation for the conduct at issue." Id. (emphasis added); see also Garavaglia v. Centra, Inc., 211 Mich.App. 625, 630, 536 N.W.2d 805 (1995). In this case, the circuit court determined that the WPA was not applicable to the facts regarding plaintiff's discharge. Because the WPA provided no remedy at all, it could not have provided plaintiff's exclusive remedy. Dudewicz, supra at 80, 503 N.W.2d 645. Therefore, we hold that the circuit court abused its discretion when it denied plaintiff's motion on the ground that the WPA provided plaintiff's exclusive remedy. Huber, supra at 576, 408 N.W.2d 505.
Although plaintiff sought reinstatement (or relief from a prior circuit court order) with respect to both her public policy and breach of contract claims, only her breach of contract claim was dismissed on the basis of the purported exclusivity of the WPA. Accordingly, plaintiff is not entitled to relief from the circuit court's order regarding her public policy claim. We therefore remand with instructions to the circuit court to (1) modify its prior order reversing the district court's judgment in favor of plaintiff with regard to plaintiff's breach of contract claim and to (2) reinstate the judgment of the district court with respect to that count only.
Affirmed in part, reversed in part, and remanded. We do not retain jurisdiction.
No taxable costs pursuant to MCR 7.219, neither party having prevailed in full.
NOTES
[1]  The circuit court construed plaintiff's public policy claim as being a claim for retaliatory discharge under the wages and fringe benefits act, M.C.L. § 408.471 et seq.; M.S.A. § 17.277(1) et seq.
[2]  In plaintiff's reply brief on appeal, she specifically states that the circuit court's ruling regarding the applicability of the WPA "is not an issue in this appeal."
[3]  In these motions, defendants argued (1) that the WPA was inapplicable because the USDL did not constitute a "public body" and (2) that plaintiff's public policy claim was excluded by the WPA.
[4]  Although plaintiff's motion was entitled "Motion For Rehearing/Reinstatement of Judgment," she explained at the first hearing on the motion and in her supplemental brief in support of the motion that, procedurally, the motion was actually a motion seeking relief from the prior circuit court order.
