[JURIST] Thailand's Constitutional Court [official website, in Thai] ruled 8-1 Tuesday that a June cabinet communique supporting the establishment of a World Heritage site on the countries' shared border was unconstitutional [PDF press release, in Thai]. In June, Thai Foreign Minister Noppadon Pattama signed the Thai-Cambodian Joint Communique, indicating Thai support for the Cambodian bid to have the 900-year-old Preah Vihear temple [Telegraph backgrounder] designated a World Heritage site. The court found that section 190 of the Thai constitution [PDF text] forbade such a move without parliamentary approval:

A treaty that provides for a change in the Thai territories, the extraterritorial areas in which the Kingdom has a sovereign right, or any jurisdictional area the Kingdom has acquired through treaty or through international law, or requires the enactment of an Act for its implementation, or has extensive impacts on the country's economic and social stability, or has significant bindings on trade, investment, or national budget, must be approved by the National Assembly.

On Monday, the United Nations Educational Scientific and Cultural Organization (UNESCO) [official website] approved the Cambodian bid [press release, in French]. After Tuesday's ruling, opposition party members said they would petition for the removal of Noppadon and eventually the entire cabinet. Reuters has more.

Tensions have long existed between Thailand and Cambodia concerning the Preah Vihear temple, as both countries have claimed jurisdiction over the structure. In 1962, the International Court of Justice (ICJ) ruled [opinion, PDF] that the temple was officially located in Cambodia.