Constitutionality of laws on maritime zones, sea lanes questioned before SC

A former professor of the University of the Philippines has asked the Supreme Court (SC) to nullify some provisions of the Philippine Maritime Zones Act (MZA) and Philippine Archipelagic Sea Lanes Act (ASLA) for being unconstitutional, saying it has enabled the navigation of Chinese vessels into the country's waters.

In a 157-page petition uploaded on the SC website, petitioner Peter Payoyo also asked the High Court to prohibit the Department of Foreign Affairs (DFA) from referring, submitting, or lodging any proposal with the International Maritime Organization on the establishment and designation of archipelagic sea lanes.

He also sought to prohibit the National Mapping and Resource Information Authority (NAMRIA) from delimiting Philippine archipelagic waters and/or Philippine internal waters as well as from crafting maps and charts.

"The unconstitutionality of these two intertwined laws stem directly from their patent breach of Article I of the Philippine Constitution," the petition read.

He specifically cited the second sentence of Article I, otherwise known as the Archipelagic Principle, which reads: "The waters around, between, and connecting the islands of the archipelago, regardless of their breadth and dimensions, form part of the internal waters of the Philippines."

Aside from this, the petitioner argued that all provisions in ASLA that seek to implement the "right of archipelagic sea lanes passage" or the "exercise of the right of archipelagic sea lanes passage" over the country's waters by foreign warships are unconstitutional and void.

"ASLA's recognition of the applicability of transit passage regime for straits in Philippine archipelagic waters is without a doubt a dramatic rejection and a complete abandonment of the Archipelagic Principle enshrined in the Constitution," it said.

"The ASLA represents the most drastic turn-around from the principled legal position consistently upheld by the Philippines… The ASLA repudiates the flagship statements and proclamations that have been put out by the Philippines to the international community," it added.

President Ferdinand "Bongbong" Marcos Jr. signed the two measures into law in November 2024.

Further, the petitioner argued that ASLA enabled the freedom of navigation of Chinese vessels in the country's archipelagic waters.

"Recent incursions of Chinese warships, government research ships, and unmanned underwater drones in Philippine archipelagic waters have certainly been a cause of serious public concern," the petition said. 

"Surprisingly, these incursions have somehow become routine and normalized as undesirable yet acceptable demonstrations of navigational freedoms," it added.

According to the petitioner after the laws were enacted, three Chinese vessels departed from Xiamen Island on route to the Pacific Ocean.

He said that two of the vessels navigated through the northernmost tip of the country while one entered the country's waters through the Mindoro Strait.

"Other than tracking the research ships to their rendezvous destination outside the Philippine EEZ east of the archipelago, the Philippine government did not protest or express official indignation against the passage of any of the alleged 'spy' ships," the petition read.

The petitioner said that under UNCLOS, the country has the right to require prior permission for any marine scientific research activity in the zones.

He also cited instances when Chinese vessels entered the country's waters in February 2025 and April 2025.

"The transformation of Philippine internal waters into archipelagic waters, brought about by the MZA, and the subsequent subjection of these waters to the right of archipelagic sea lanes passage by China's warships, courtesy of ASLA, could not come at a worse time in China-Philippine relations, especially for the Philippines," it said.

"At this juncture of unprecedented tensions between the two countries and deepening geopolitical disputes in the region, the ASLA's facilitation of unhindered warship access to Philippine territorial and coastal waters bodes ill for Philippine national security," it added.

The respondents are former Executive Secretary Lucas Bersamin; Theresa Lazaro, in her capacity as Foreign Affairs Secretary, and Peter Tiangco, in his capacity as NAMRIA administrator.

GMA News Online has reached out to the Office of the Executive Secretary and the other respondents and will publish their response once available. — VDV, GMA News