The Supreme Court upheld on Tuesday the constitutionality of the congressional approval of President Rodrigo Duterte's request for one-year extension of martial law in southern Philippines.

Voting 10-5, the SC said it has no power to review the decision of Congress, a separate and equal branch of government, to grant Duterte's request to extend martial law from Jan. 1 to Dec. 31 this year.

The decision was reached following the filing of separate petitions of former Commission on Elections chair Christian Monsod, former Commission on Human Rights chairperson Loretta Ann Rosales, a group of congressmen led by Albay 1st District Rep. Edcel Lagman and another group led by Bayan Muna Rep. Carlos Zarate and Anakpawis Rep. Ariel Casilao seeking to lift martial law extension in Mindanao.

"Each House of Congress has full discretionary authority to formulate, adopt and promulgate its own rules; the exercise of this power is generally exempt from judicial supervision and interference," the decision penned by Associate Justice Noel Tijam said.

The nine justices who concurred in the ruling were Associate Justices Presbitero Velasco Jr., Teresita Leonardo - De Castro, Diosdado Peralta, Lucas Bersamin, Mariano Del Castillo, Estela Perlas - Bernabe, Samuel Martires, Andres Reyes Jr. and Alexander Gesmundo.

Chief Justice Ma. Lourdes Sereno, Senior Associate Justice Antonio Carpio, Associate Justices Marvic Leonen, Francis Jardeleza and Alfredo Benjamin Caguioa dissented.

The high court explained that it could only step in once there is clear showing of arbitrary and improvident use of such power by Congress under Article VII, Section 18 of the 1987 Constitution, which it said is lacking in this case.

It also disagreed with the argument of petitioners that the extension should have only been limited to 60 days, saying the Constitution does not fix a period of duration for such extension and is also actually silent as to how many times the Congress can extend martial law declaration by the President.

The SC held that the factual bases for the martial law declaration remain in Mindanao, citing the facts submitted by the Armed Forces during oral arguments last month.

"The rebellion that spawned the Marawi incident persists. Public safety requires the extension, as shown by facts presented by the AFP," it said.

Duterte has placed the entire Mindanao under martial law shortly after the Islamic State-inspired Maute terrorists attacked and occupied Marawi on May 23 last year. Intense fighting ensued between the government troops and the terrorists lasting for about five months until October. DMS