Palang Pracharath Party (PPRP) deputy leader Paiboon Nititawan has petitioned the Constitutional Court to rule on whether the 2001 Thai-Cambodian memorandum of understanding on joint development in the Gulf of Thailand breaches the Thai constitution.
He said he had previously asked the Ombudsman to petition the court to rule on the matter on April 10, but the Ombudsman had failed to do so within the 60-day deadline. He then decided to contact the court directly.
Mr Paiboon said the 2001 MoU had not been approved by the Thai parliament before it was signed, which has resulted in it "having no legal effect from inception".
He said he asked the court to rule whether the Department of Treaties and Legal Affairs and the Ministry of Foreign Affairs should be held responsible for what he believed was a constitutional breach.
Mr Paiboon said despite previously acknowledging that the MoU had not won parliamentary approval, the department and the ministry continue using it as a reference to what has been agreed by both nations regarding the 26,000 square kilometres of territorial waters in the Gulf of Thailand, which Thailand has sovereignty over.
Mr Paiboon said he also asked the court to order the department and the ministry to stop using the 2001 MoU in its work pertaining to the demarcation of the territorial waters in question.
Previously, Mr Paiboon said if the court rules the 2001 MoU to be unconstitutional and has no legal effect based on the grounds it was incomplete from the start, as stated in the 1969 Vienna Convention on the Law of Treaties, Thailand would be in a better position when fresh disputes over Thai-Cambodian overlapping claims arise.
He said Cambodia has always cited the 2001 MoU to back its position that Thailand had formally recognised these territorial waters as both nations' areas of overlapping claims.
Foreign Affairs Minister Maris Sangiampongsa said earlier that the 2001 Thai-Cambodian MoU was not a treaty and contained no obligatory clauses. The two governments have not made any agreement regarding the MoU.
Mr Maris said the MoU does nothing to compromise Thailand's sovereignty over an overlapping claims area (OCA) in Koh Kood in the border province of Trat, as it imposes no obligations.
More issues need to be thrashed out pending the court's decision, he said.
