The President of the Philippines possesses the discretionary power to ratify treaties, including the decision of whether and when to submit a signed treaty to the Senate for concurrence; this act is not a ministerial duty compellable by a writ of mandamus.

The Philippines, through its Charge d' Affaires, signed the Rome Statute of the International Criminal Court (ICC) on December 28, 2000. The Rome Statute establishes the ICC to prosecute individuals for genocide, crimes against humanity, war crimes, and the crime of aggression, and its provisions require ratification, acceptance, or approval by signatory states for it to become binding. Petitioners, concerned with human rights and the enforcement of international criminal law, urged the executive department to transmit the signed Statute to the Senate for its concurrence to complete the ratification process.

• The Rome Statute of the International Criminal Court was opened for signature on July 17, 1998, and the Philippines signed it on December 28, 2000, through Charge d' Affaires Enrique A. Manalo.
• The Rome Statute requires ratification, acceptance, or approval by signatory states for its provisions to become binding.
• Petitioners, including Senator Aquilino Pimentel, Jr., and various human rights organizations, filed a petition for mandamus to compel the Office of the Executive Secretary and the Department of Foreign Affairs to transmit the signed Rome Statute to the Philippine Senate for its concurrence, as mandated by Section 21, Article VII of the 1987 Constitution.
• Petitioners argued that ratification is a Senate function and that the executive department has a ministerial duty to transmit the treaty for Senate concurrence.
• Respondents, represented by the Office of the Solicitor General, questioned the petitioners' legal standing and argued that the executive department has no duty to transmit the Rome Statute to the Senate for concurrence.

• The ratification of a treaty, under both domestic and international law, is a function of the Senate, and thus the executive department has a ministerial duty to transmit the signed Rome Statute to the Senate.
• The Philippines has a ministerial duty to ratify the Rome Statute under treaty law and customary international law, citing the Vienna Convention on the Law of Treaties which enjoins states to refrain from acts defeating the object and purpose of a treaty they have signed prior to ratification.
• Senator Pimentel has legal standing as a member of the Senate whose power to concur in treaties is allegedly being impaired.
• Other petitioners, as human rights advocates, citizens, and under the doctrine of inter-generational rights, claim legal standing.

• The petitioners, except potentially Senator Pimentel, lack legal standing to file the suit.
• The petition violates the rule on hierarchy of courts.
• The executive department has no ministerial duty to transmit the Rome Statute to the Senate for concurrence, as treaty ratification is a discretionary power of the President.
• The signing of a treaty does not automatically bind the state nor compel its ratification.

• Whether the petitioners have legal standing to file the petition for mandamus.
• Whether the Executive Secretary and the Department of Foreign Affairs have a ministerial duty to transmit the signed copy of the Rome Statute to the Senate for its concurrence.

• Only Senator Aquilino Pimentel, Jr. has legal standing to file the suit. As a legislator, he has standing to question any official action that infringes upon his prerogatives and the powers of the Senate, particularly its power to concur in treaties. The other petitioners failed to show direct injury from the non-transmittal of the Rome Statute.
• The Executive Secretary and the Department of Foreign Affairs do not have a ministerial duty to transmit the signed Rome Statute to the Senate. The President has the sole authority to negotiate and enter into treaties, and ratification is an executive act. While the Constitution requires Senate concurrence for a treaty to be valid and effective, the power to ratify itself belongs to the President. The decision to submit a treaty to the Senate for concurrence is within the President's discretion, which cannot be compelled by mandamus.
• The signing of a treaty (an act of authentication and good faith) is distinct from ratification (the formal act by which a state confirms and accepts the treaty's provisions). The President, after a treaty is signed, has the discretion to study its contents and decide whether or not to ratify it, considering the national interest.
• Executive Order No. 459 outlines the domestic procedure: after signing, a treaty is transmitted to the Department of Foreign Affairs, which prepares ratification papers for the President. Only after the President ratifies the treaty is it submitted to the Senate for concurrence.
• The Vienna Convention on the Law of Treaties does not compel ratification but obliges a signatory state not to defeat the object and purpose of a treaty prior to its entry into force or until it makes clear its intention not to become a party. This does not remove the President's discretion to ratify.
• The Court has no jurisdiction to enjoin the President in the performance of official duties or to compel the executive branch to transmit the Rome Statute to the Senate. The petition was dismissed.

• Mandamus — A writ issued when any tribunal, corporation, board, officer or person unlawfully neglects the performance of an act which the law specifically enjoins as a duty resulting from an office, trust, or station. It was not applied here because the act sought (transmittal of treaty to Senate) was deemed discretionary, not ministerial.
• Legal Standing (Locus Standi) — A personal and substantial interest in the case such that the party has sustained or will sustain direct injury as a result of the governmental act being challenged. Applied to find that only Senator Pimentel had standing, as the non-transmittal potentially impaired the Senate's power of concurrence.
• Treaty-Making Process — Involves negotiation, signature, ratification, and exchange of instruments of ratification. The Court clarified that signature authenticates the treaty text but does not signify final consent where ratification is required. Ratification is the formal executive act of confirming and accepting the treaty's provisions, which then requires Senate concurrence to be valid and effective under Philippine law.
• President's Power in Foreign Relations and Treaty-Making — The President is the sole organ and authority in external relations, with the sole authority to negotiate treaties and the power to ratify them. This power is subject to the Senate's concurrence for treaties. The Court affirmed the President's discretion in deciding whether to ratify and submit a treaty to the Senate.
• Senate's Role in Treaty-Making — The Senate's role is limited to giving or withholding its consent (concurrence) to the ratification made by the President; it does not ratify the treaty itself.
• Checks and Balances — The requirement of Senate concurrence for treaties serves as a check on the executive's power in foreign relations. The Court upheld this balance by affirming the distinct roles of the President (ratification) and the Senate (concurrence).
• Vienna Convention on the Law of Treaties (Article 18) — Obligation not to defeat the object and purpose of a treaty prior to its entry into force. The Court held that this provision does not compel a state to ratify a treaty it has signed, nor does it remove the President's discretion in the ratification process.
• Separation of Powers — Impliedly invoked by the Court in refusing to compel the President, an act which would encroach upon the executive's discretionary powers concerning foreign relations and treaty-making.
• Executive Order No. 459 (Guidelines in the Negotiation of International Agreements and its Ratification) — This executive order details the domestic process for treaty ratification, requiring the President's ratification before submission to the Senate for concurrence. It was cited to show the established procedure that underscores the President's role in ratifying.

• "Ratification, which is the next step, is the formal act by which a state confirms and accepts the provisions of a treaty concluded by its representatives. The purpose of ratification is to enable the contracting states to examine the treaty more closely and to give them an opportunity to refuse to be bound by it should they find it inimical to their interests."
• "It should be emphasized that under our Constitution, the power to ratify is vested in the President, subject to the concurrence of the Senate. The role of the Senate, however, is limited only to giving or withholding its consent, or concurrence, to the ratification."
• "This Court has no jurisdiction over actions seeking to enjoin the President in the performance of his official duties."

• Oposa vs. Factoran, Jr., 224 SCRA 792 (1993) — Referenced in relation to the petitioners Bianca Hacintha Roque and Harrison Jacob Roque suing under the doctrine of inter-generational rights for legal standing, though the Court ultimately did not grant them standing on this basis for this specific case.
• Legaspi vs. Civil Service Commission, 150 SCRA 530 (1987) — Cited for the principle that a petitioner for mandamus must be an aggrieved party possessing a clear legal right to be enforced.
• Joya vs. Presidential Commission on Good Government, 225 SCRA 568 (1993) — Cited for the definition of "legal standing" as a personal and substantial interest in the case.
• Gonzales vs. Narvasa, 337 SCRA 733 (2000) — Cited in the context of legal standing, requiring a personal stake in the outcome to ensure concrete adverseness.
• Del Mar vs. Philippine Amusement and Gaming Corporation, 346 SCRA 485 (2000) — Cited for the principle that legislators have standing to sue if the powers of Congress are impaired.
• Bayan vs. Zamora, 342 SCRA 449 (2000) — Cited for the importance of legislative participation in treaty-making as a check on executive power and for the distinction between executive agreements and treaties, and the process of ratification.
• Severino vs. Governor-General, 16 Phil. 366 (1910) — Cited for the principle that the Court has no jurisdiction over actions seeking to enjoin the President (or then, Governor-General) in the performance of official duties.

• 1987 Constitution, Article VII, Section 21 — "No treaty or international agreement shall be valid and effective unless concurred in by at least two-thirds of all the Members of the Senate." This was central to the petitioners' argument that the Senate has a role, but the Court clarified this role is concurrence to the President's ratification.
• 1935 Constitution, Article VII, Section 10(7) — "The President shall have the power, with the concurrence of two-thirds of all the Members of the Senate, to make treaties xxx." Cited to show historical precedent for Senate involvement in treaty-making.
• 1973 Constitution, Article VIII, Section 14(1) — "Except as otherwise provided in this Constitution, no treaty shall be valid and effective unless concurred in by a majority of all the Members of the Batasang Pambansa." Cited to show historical precedent for legislative involvement in treaty-making.
• Rules of Civil Procedure, Rule 65, Section 3 — Defines when a petition for mandamus may be filed. Its requirements were not met as the act sought was not a ministerial duty.
• Rome Statute of the International Criminal Court, Article 1 — Establishes the ICC and its complementary jurisdiction.
• Rome Statute of the International Criminal Court, Article 5 — Defines the crimes within the ICC's jurisdiction.
• Rome Statute of the International Criminal Court, Article 25 — States that the Statute is subject to ratification, acceptance or approval by signatory states.
• Vienna Convention on the Law of Treaties, Article 18 — "Obligation not to defeat the object and purpose of a treaty prior to its entry into force." Petitioners invoked this to argue for a duty to ratify, but the Court held it does not compel ratification.
• Executive Order No. 459, Section 7 — "Domestic Requirements for the Entry into Force of a Treaty or an Executive Agreement." This EO outlines the steps for treaty ratification in the Philippines, emphasizing the President's role in ratifying before Senate concurrence.