The Hong Kong-based Asia Pacific Institute of International Law (APIIL) said on Tuesday that they are still awaiting a reply from the tribunal and have asked for an opportunity to present the case orally.

On June 6, 2016, the Hong Kong legal organization has submitted an amicus curiae (friend of the court) brief on the arbitration initiated by the Philippines to the tribunal. Citing a lot of international cases, the legal document addresses two key issues: jurisdiction of PCA to determine the Philippines’ 15 submissions of the arbitration and justiciability of the issues raised in the submissions.

The brief was endorsed by several solicitors and legal experts from China's Hong Kong, Britain and Australia. One of the experts Natalie Klein, professor and dean of Macquarie Law School in Sydney, told People’s Daily that the purpose of the brief was to highlight issues in the arbitration over which the Tribunal does not have jurisdiction or aspects of the dispute that were not justiciable.

“For these issues, the primary form of dispute settlement available to the parties would instead be negotiations,” she said, “such an arbitration involving sovereignty issues should not be handled by PCA under the framework of the United Nations Convention on the Law of the Sea (UNCLOS).”

At the heart of the disputes between China and the Philippines is the latter's illegal occupation of Chinese reefs and islets in the South China Sea. Mi Chenxi, associate fellow of the China Institute for Marine Affairs attached to the State Oceanic Administration, told People’s Daily, “categorizing maritime features is in essence subject to territorial sovereignty, which is beyond the scope of UNCLOS. Hence the arbitral tribunal has accepted submissions over which it does not have jurisdiction in the first place.”

“The brief has asked for the Tribunal to hear oral arguments from the amicus. We have not yet had a response on this request,” Klein revealed, “it is our hope that it will be given due consideration in the Tribunal's deliberations before they issue their final judgment.”

The Philippines unilaterally initiated arbitration proceedings to the Hague-based PCA against China over the South China Sea disputes in 2013. PCA ruled in 2015 that it has the jurisdiction over the case, taking up seven of the 15 submissions made by Manila.

The Chinese government has reiterated its non-acceptance and non-participation stance in the case.

An amicus curiae (literally, friend of the court) is someone as a third party to a case and offers information that bears on the case but who has not been solicited by any of the parties to assist a court. This may take the form of legal opinion or testimony and is a way to introduce concerns ensuring that the possibly broad legal effects of a court decision will not depend solely on the parties directly involved in the case.