HONG KONG/TAIPEI • A Taiwanese group has intervened in the Philippines' international court case against China's claims in the South China Sea, pressing Taipei's position that Taiwan is entitled to a swathe of the disputed waterway as an economic zone.
The unusual submission has emerged just as judges at the Permanent Court of Arbitration in The Hague are poised to rule on the Philippines' landmark case, brought under the United Nations Convention on the Law of the Sea (Unclos).
The move could delay the judges' ruling - now expected within two months - and potentially complicates worsening territorial disputes that are roiling across the vital trade route.
Last month, the judges allowed written evidence from the government-linked Chinese (Taiwan) Society of International Law, even though Taiwan is neither a member of the UN nor a signatory to Unclos, legal and diplomatic sources told Reuters.
As well as reviewing several hundred pages of evidence from Taiwan, the judges have sought further information from the Philippines and China, said legal sources close to the case.
Manila is challenging the legality of China's claims to virtually the entire South China Sea, in part by arguing that no reefs, atolls or islets in the Spratly archipelago can legally be considered an island, and therefore China holds no rights to a 370km exclusive economic zone (EEZ).
Taiwan's single holding of Itu Aba is the biggest feature in the Spratlys and the one that some analysts believe has the strongest claim to island status and an economic zone.
The Spratlys are also claimed by China, Vietnam and Malaysia, while Brunei claims nearby waters.
Taiwanese officials have bristled at the Philippines' earlier evidence that Itu Aba is a "rock" that cannot support natural human habitation and so has no claims on either island status or an EEZ.
Citing various government reports and statements as evidence, the society's submission to the court states that "it is clear that Taiping Island (Itu Aba) is an island which can sustain human habitation and economic life of its own under... Unclos".
The Taiwanese move comes amid rising tension, with Beijing and Washington accusing each other of militarising the area as China builds facilities on its recent reef reclamations and the United States increases patrols, exercises and overflights.
Reiterating Beijing's non-acceptance of the case, China's Foreign Ministry said the Philippines was using the case to negate China's territorial sovereignty.
"Chinese people on both sides of the Taiwan Strait all have a responsibility to jointly protect the ancestral property of the Chinese people," the ministry said in a faxed reply to Reuters.
While the society is technically operating as a private body, it has close ties to Taipei, including President Ma Ying-jeou, who once headed the institution and is still on the board.
Chinese officials have repeatedly challenged the court's jurisdiction and the rights of the Philippines to bring the case, refusing to participate.
Taiwan, regarded by Beijing as a breakaway province, was not invited to participate in any way.
Vietnam has provided a submission in support of the Philippines' arguments that the court has jurisdiction.