a Decision G.R. No. 201273 14 have any interest in the outcome of this case. Instead, they would like the Court to rule on the constitutionality of Section 53 of the IPRA. Based on their own allegations, therefore, intervention is improper. Further, ruling on the constitutionality of Section 53 will delay the adjudication of the issue of whether the RTC has jurisdiction over the Republic's Complaint. More importantly, even if allowed to intervene, the issue on the constitutionality of Section 53 of the IPRA is not the very lis mota of this Petition of the Republic. As the Court held in Spouses Mirasol v. Court ofAppeals: 53 Jurisprudence has laid down the following requisites for the exercise of this power: First, there must be before the Court an actual case calling for the exercise of judicial review. Second, the question before the Court must be ripe for adjudication. Third, the person challenging the validity of the act must have standing to challenge. Fourth, the question of constitutionality must have been raised at the earliest opportunity, and lastly, the issue of constitutionality must be the very lis mota of the case. As a rule, the courts will not resolve the constitutionality of a law, if the controversy can be settled on other grounds. The policy of the courts is to avoid ruling on constitutional questions and to presume that the acts of the political departments are valid, absent a clear and unmistakable showing to the contrary. To doubt is to sustain. This presumption is based on the doctrine of separation of powers. This means that the measure had first been carefully studied by the legislative and executive departments and found to be in accord with the Constitution before it was finally enacted and approved. The present case was instituted primarily for accounting and specific performance. The Court of Appeals correctly ruled that PNB's obligation to render an accounting is an issue, which can be determined, without having to rule on the constitutionality of P.D. No. 579. In fact there is nothing in P.D. No. 579, which is applicable to PNB's intransigence in refusing to give an accounting. The governing law should be the law on agency, it being undisputed that PNB acted as petitioners' agent. In other words, the requisite that the constitutionality of the law in question be the very lis mota of the case is absent. Thus we cannot rule on the constitutionality of P.D. No. 579. 54 a Here, it is unnecessary to rule on the constitutionality of Section 53 of the IPRA in order to arrive at the conclusion that the RTC has jurisdiction over the Republic's Complaint. WHEREFORE, premises considered, the Petition is PARTLY GRANTED. The Decision dated February 13, 2012 of the Court of Appeals in C.A. G.R. SP No. 116926 is REVERSED and SET ASIDE. The case is REMANDED to the Regional Trial Court of Baguio City, Branch 6 which is directed to proceed with dispatch with the trial on the merits as well as the resolution of Civil Case No. 7200-R. The Petition-in-Intervention of the Heirs of Mateo Carifio and Bayosa Ortega is DENIED for lack of merit. 53 54 403 Phil. 760 (200 I). Id. at 773-774.