G.R. No. 83828 . November 16, 1989. LEONOR MAGDANGAL, ET AL., petitioners, vs. CITY OF OLONGAPO, DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES AND/OR DIRECTOR OF THE BUREAU OF LANDS, THE REGISTRY OF DEEDS OF OLONGAPO CITY and HON. SOLICITOR GENERAL, respondents.
FACTS

Petitioners, members of the Pag-asa Lot Owners Association, Inc., built their houses on Lot 21 within a National Park Reservation in Olongapo City. Batas Pambansa Blg. 875 excluded this lot from the reservation and ceded its ownership to the Olongapo City government for use as a cultural, trade, and tourism center. Petitioners challenged the constitutionality of this law, alleging it impaired contractual obligations and deprived them of property without due process.
This was not the first judicial challenge. In a prior case, G.R. No. 71362, entitled “Pag-asa Lot Owners Association, Inc., et al. v. The City Mayor of Olongapo and/or Olongapo City, et al.,” the same petitioners, including their association, directly assailed the constitutionality of B.P. Blg. 875. The Supreme Court, in a Resolution dated October 9, 1985, dismissed that petition for lack of merit. The present petition for prohibition raises the identical constitutional challenge.

ISSUE

Whether the present petition for prohibition, challenging the constitutionality of Batas Pambansa Blg. 875, is barred by the doctrine of res judicata due to the prior dismissal in G.R. No. 71362.

RULING

Yes, the petition is barred by res judicata. The Court applied the settled rule that a final judgment on the merits by a court with jurisdiction is conclusive in a subsequent case between the same parties involving the same subject matter and cause of action. All requisites for res judicata are present. First, the Resolution in G.R. No. 71362 dismissing the petition for lack of merit had long become final. Second, the Supreme Court unquestionably had jurisdiction over the constitutional issue and the parties. Third, a dismissal for lack of merit, even via a minute resolution, constitutes a judgment on the merits. Fourth, there is identity of parties, subject matter, and cause of action. The petitioners here were also petitioners in the prior case, the subject is the constitutionality of the same law, and the core cause of action—that the law impairs contracts and constitutes deprivation without due process—is identical. The Court emphasized that a party cannot escape res judicata by merely varying the form of action, from a petition for declaratory relief to a petition for prohibition, when the fundamental cause remains the same. Consequently, the constitutional issue having been squarely raised and adjudicated, the present action is barred. The petition was dismissed.