Joint exploration and exploitation of resources in the West Philippine Sea with China is unconstitutional, acting Chief Justice Antonio Carpio said yesterday. "Joint exploration and exploitation is prohibited in our Constitution, which requires that the Philippines shall have 'full control and supervision' in the exploration and exploitation of natural resources," he explained in a text message. But at a forum over the weekend, Carpio said allowing Chinese participation in oil and gas exploration through Philippine service contracts might be acceptable. The signing of a memorandum of understanding (MOU) on oil and gas exploration during the recent visit of Chinese President Xi Jinping had sparked concerns the country’s sovereign rights over the West Philippine Sea would be compromised.

Punay, E., & Flores, H. (2018, November 27). 'Joint exploration, exploitation in WPS unconstitutional'. The Philippine Star, p. 4.