Save the Mekong, a coalition of 39 civil society groups and non-government organisations, sent a letter to the Mekong River Commission (MRC) Council on the eve of their three-day meeting in Siem Reap, Cambodia, at which the fate of the dam is to be decided.
The letter coincided with an advertisement campaign launched by the group in newspapers in Thailand and Cambodia that called on the prime ministers of those countries and of Laos and Vietnam to oppose the controversial hydropower project.
"Our message is simple: Protecting the Mekong River is vital to ensuring healthy fisheries, abundant agriculture, and supporting the livelihoods and food security of millions of people in the region," said Chhith Sam Ath, a spokesman for the non-profit Forum on Cambodia.
"As the first hydropower dam proposed for the Mekong River's mainstream, the dam's devastating impacts to river's ecosystem, fisheries, and river-based livelihoods is likely to lead to serious cross-border conflict," he said.//DPA