A former professor from the University of the Philippines has petitioned the Supreme Court of the Philippines to strike down provisions of two recently enacted maritime laws, claiming they are unconstitutional and have exposed Philippine waters to foreign vessels, particularly from China.
In a 157-page petition uploaded on the SC website, petitioner Peter Payoyo sought to nullify parts of the Philippine Maritime Zones Act (MZA) and the Philippine Archipelagic Sea Lanes Act (ASLA).
He also urged the Court to prohibit the Department of Foreign Affairs from submitting proposals to the International Maritime Organization on archipelagic sea lanes, and to stop the National Mapping and Resource Information Authority from delimiting Philippine waters or producing related 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 stated, citing the Archipelagic Principle: “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.”
Payoyo argued that ASLA’s provisions allowing “the right of archipelagic sea lanes passage” for foreign warships violate this principle.
“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,” the petition said.
He added that the law 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.”
President Ferdinand Marcos Jr. signed both measures into law in November 2024.
The petition further alleged that ASLA has enabled Chinese vessels to freely navigate Philippine 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,” it said.
“Surprisingly, these incursions have somehow become routine and normalized as undesirable yet acceptable demonstrations of navigational freedoms.”
Payoyo cited incidents involving Chinese vessels departing from Xiamen Island and passing through Philippine waters en route to the Pacific Ocean, including routes near the country’s northern tip and via the Mindoro Strait. He noted that no formal protests were lodged by the government over these passages.
He also pointed to vessel entries in February and April 2025, emphasizing that under the United Nations Convention on the Law of the Sea, the Philippines has the right to require prior permission for marine scientific research within its maritime zones.
“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,” the petition 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.”
Named respondents in the case include former Executive Secretary Lucas Bersamin, Foreign Affairs Secretary Theresa Lazaro, and NAMRIA Administrator Peter Tiangco.