Can President order Senate to stop corruption probe?

ANC 24/7 reports: "Philippine senators are undeterred by President Rodrigo Duterte's demand for them to stop probing alleged fund anomalies. They vow to continue doing it in line with their jobs."[1]To answer the question, no, the President of the Philippines has no power to stop the Senate from conducting its probe on alleged corruptions in the Executive Branch. Hence, Senators are correct and justified in ignoring the orders of the President to stop their investigation.

The Senate, being one chamber of the Legislative Department, enjoys independence flowing from the principle of separation of powers. According to the case of Angara v. Electoral Commission,[2] the separation of powers is a fundamental principle in our system of government. It obtains not through express provision but by actual division in our Constitution. Each department of the government has exclusive cognizance of matters within its jurisdiction, and is supreme within its own sphere.[3]

The principle of separation of powers is implied in the division of powers in the Constitution among the three (3) government branches: the executive, the legislative, and the judiciary. The principle presupposes mutual respect by and between the executive, legislative, and judicial departments of the government and calls for them to be left alone to discharge their duties as they see fit.[4]

It is undisputed that the Senate has the power to conduct inquiries. No less than the 1987 Constitution recognizes this power, viz:
The Senate or the House of Representatives or any of its respective committees may conduct inquiries in aid of legislation in accordance with its duly published rules of procedure. The rights of persons appearing in, or affected by, such inquiries shall be respected.[5]
The heads of departments may, upon their own initiative, with the consent of the President, or upon the request of either House, as the rules of each House shall provide, appear before and be heard by such House on any matter pertaining to their departments. Written questions shall be submitted to the President of the Senate or the Speaker of the House of Representatives at least three days before their scheduled appearance. Interpellations shall not be limited to written questions, but may cover matters related thereto. When the security of the State or the public interest so requires and the President so states in writing, the appearance shall be conducted in executive session.[6]
The Supreme Court has recognized this power and even described the extent of the Senate's prerogatives in these inquiries, thus:
Legislative inquiries, unlike court proceedings, are not subject to the exacting standards of evidence essential to arrive at accurate factual findings to which to apply the law. Hence, Section 10 of the Senate Rules of Procedure Governing Inquiries in Aid of Legislation provides that "technical rules of evidence applicable to judicial proceedings which do not affect substantive rights need not be observed by the Committee." Court rules which prohibit leading, hypothetical, or repetitive questions or questions calling for a hearsay answer, to name a few, do not apply to a legislative inquiry. Every person, from the highest public official to the most ordinary citizen, has the right to be presumed innocent until proven guilty in proper proceedings by a competent court or body.[7]
Senate and House inquiries have been described as "constitutional prerogative [of Congress] to inform itself" and power "to access information."[8]

However, the power of both houses of Congress to conduct inquiries in aid of legislation is not absolute or unlimited. Its exercise is circumscribed by the afore-quoted provisions of the Constitution. Thus, as provided therein, the investigation must be "in aid of legislation in accordance with its duly published rules of procedure" and that "the rights of persons appearing in or affected by such inquiries shall be respected." It follows then that the rights of persons under the Bill of Rights must be respected, including the right to due process and the right not to be compelled to testify against one's self.[9]

[1] ANC 24/7 (2021). Senators ignore Duterte's demand to stop corruption probe.

[2] G.R. No. L-45081, July 15, 1936.



[5] Section 21, Article XI, 1987 Constitution.

[6] Section 22, supra note 5.

[7] G.R. No. 180643, September 4, 2008.

[8] Rosenberg, M. (2017). When Congress Comes Calling, citing

[9] G.R. No. 89914, November 20, 1991.