THE PHILIPPINE Supreme Court (SC) has voided a 2005 government deal with China and Vietnam for joint gas and oil explorations in the South China Sea.

Voting 12-2 with one abstention, the tribunal had ruled the agreement violated the Constitution for allowing foreigners to explore the country’s natural resources covering 142,886 square kilometers without full supervision from the state, it said in a statement on Tuesday.

“The court ruled that the Joint Marine Seismic Undertaking 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,” it said.

The High Court had yet to upload a copy of the decision on its website.

Under the Constitution, the exploration, development and use of the country’s natural resources must be under the full control and supervision of the state.

In 2005, the Philippines under ex-President Gloria Macapagal-Arroyo entered into the deal with China and Vietnam through their state-owned oil companies.

The government earlier argued the deal was aboveboard because it only involved “pre-exploration activities,” which the court disagreed with.

The High Court said the purpose of the pact was for these companies to explore the area for petroleum and other gas resources.

“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,” it said.

Bayan Muna Party-list including former Congressmen Satur C. Ocampo and Teodoro A. Casiño sued the government in 2008 before the High Court, saying the deal would allow foreign oil companies to conduct large-scale explorations of natural resources intended for Filipino citizens.

In a statement, Mr. Casiño welcomed the ruling even if it took the court almost 15 years to resolve it. “The ruling is as relevant as ever considering President Ferdinand R. Marcos, Jr.’s plan to enter into a joint exploration of the West Philippine Sea with China,” he said, referring to areas of the South China Sea within the Philippines’ exclusive economic zone.

Last week, Chinese President Xi Jinping told Mr. Marcos China was ready to resume oil and gas talks with the Philippines, according to Chinese state television.

“I really hope — I would very much like, as you have suggested, Mr. President — to be able to announce that we are continuing negotiations and that we hope that these negotiations will bear fruit,” Mr. Marcos told the Chinese leader, according to a video released by the presidential palace in Manila.

“Because the pressure is upon not only China, not only the Philippines but the rest of the world to move away from the traditional fronts of power,” he added.

China claims more than 80% of the South China Sea, which is believed to contain substantial oil and gas deposits and through which billions of dollars in trade passes each year. A United Nations-backed arbitration court in July 2016 voided China’s claim to more than 80% of the sea based on a 1940s map.

China has ignored the ruling, which has failed to stop its island-building activities in areas also claimed by the Philippines, Vietnam, Brunei, Malaysia and Taiwan.

“May this be a warning to Mr. Marcos not to trifle with the constitutional provisions that reserve the exploitation of our natural resources exclusively to Filipinos and under the full supervision and control of the Philippine government,” Mr. Casiño said. — John Victor D. Ordoñez