MANILA (UPDATED) — The Supreme Court on Tuesday struck down a 2005 agreement for Joint Marine Seismic Undertaking (JMSU) among the Philippines, China, and Vietnam in the South China Sea, approved by the administration of then-President Gloria Macapagal-Arroyo.

The deal gave the 3 countries, through their oil companies Philippine National Oil Co., China National Offshore Oil Corp., and Vietnam Oil and Gas Corp., the authority to “engage in a joint research” on sources of petroleum in a 142,886 square kilometer area in the South China Sea as a pre-exploration activity.

Voting 12-2-1, the Supreme Court en banc "declared unconstitutional and void" the tripartite agreement, according to the the SC Public Information Office.

"The Court ruled that the JSMU is unconstitutional for allowing wholly-owned foreign corporations to participate in the exploration of the country's natural resources without observing the safeguards provided in Section 2, Article XII of the 1987 Constitution," the SC-PIO said in a press release.

The petitioners, then lawmakers Satur Ocampo and Teodoro Casiño, said the constitution reserves the exploration, development, and utilization (EDU) of natural resources to Filipino citizens, or corporations or associations where at least 60 percent of capital is owned by Filipinos.

They argued that the JSMU was illegal as it allowed foreign corporations wholly-owned by China and Vietnam to undertake large-scale exploration of the country's petroleum resources.

Respondents, on the other hand, maintained that constitutional provision was inapplicable because the JMSU only involves pre-exploration activities.

Bayan Muna chairman Neri Colmenares, who also served as counsel for the petitioners along with Atty. Julius Matibag, welcomed the Supreme Court's decision, saying it "would serve as another layer of protection to safeguard our territory and resources."

"As it is, China was the only one able to discover the location of rich marine resources in the area because of information gathered through the JMSU which China did not share with the Philippines. During a congressional hearing on the issue, the DFA admitted that China only gave us uselessly blurred pictures of the area. It was not a joint undertaking after all," Colmenares said.

"Tuso ang China kaya nilabanan na ng Bayan Muna ang China noon pa mang 2008. We have always challenged the administration of then Pres. Gloria Arroyo to report to the people what it has gained from the JMSU, but it has failed to do so. Because the JMSU did not benefit the Philippines," he added.

"May this ruling serve as a warning to those planning to sell out our country's resources and kowtow to the wishes of powerful nations," the Bayan Muna solo said.

• SC asked to rule on petition seeking to nullify 2005 joint exploration deal

WHAT THE COURT SAID

However, the Court said that it is clear that the deal "was executed for the purpose of determining if petroleum exists in the agreement area," according the SC-PIO.

“That the Parties designated the joint research as a 'preexploration activity' is of no moment,” said the Court. “Such designation does not detract from the fact that the intent and aim of the agreement is to discover petroleum which is tantamount to 'exploration.'"

And because the JMSU involves the exploration of the country's petroleum resources, the Court further held that it falls within the constitutional provision which mandates that the exploration, development and utilization of natural resources shall be under full control and supervision of state.

SC Associate Justice Samuel Gaerlan wrote the decision. Chief Justice Alexander Gesmundo and 10 other justices voted in favor of the ruling.

Only Associate Justices Amy Lazaro-Javier and Rodil Zalameda dissented while Associate Justice Ramon Hernando was on leave.

WHY IT MATTERS

The 2005 agreement ended in 2008 but Bayan Muna had wanted the SC to rule on the issues in the case because of the possibility that a similar agreement might be signed again.

Over 1/6 of the agreement area, according to Bayan Muna, indisputably belongs to the Philippines.

In addition, the area also includes 80 percent of the Spratly Group of Islands which the country is claiming as part of its territorial and maritime jurisdiction.

In a statement, Bayan Muna alleged that China became aggressive after the JMSU because it managed to pinpoint the exact location of natural gas and oil reserves in the area.

In contrast, the Philippines was only given blurred images and vague data despite the JMSU provision that all information gathered should be equally shared among the 3 countries, the group said.

“Tuso ang gobyerno ng Tsina, bakit magtitiwala tayong mga Pilipino dito? Dapat pigilan ito,” Colmenares earlier said.

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— With a report from Mike Navallo, ABS-CBN News