The ascetic group is adding its moral weight to mounting calls for the prime minister to step down.
Under a roof of brown tarpaulin erected on a public square, Chamlong Srimuang sits calmly, waiting for another all-night protest to begin. A former army general and politician, he knows the tactics of patience and persistence.
But today, Mr. Chamlong leads a different kind of army - barefoot Buddhist ascetics who have turned their backs on modernity, but not on politics. Called the "Dharma Army," they belong to Santi Asok, a breakaway sect of about 10,000 that runs nine self-sufficient communities known for strict monastic discipline. Its codes include sexual abstinence and a diet of one meal per day. Their name comes from the concept Dharma, which includes truth, righteousness, and integrity.
Dharma's numbers are modest- around 1,000 or so have heeded the call to join the protest. But their moral voice carries far in the political turmoil that has gripped Thailand and forced embattled Prime Minister Thaksin Shinawatra to call snap elections in April.
Among them is Santi Asok follower Nungput Vimuttinun, who marched on Sunday with tens of thousands of anti-Thaksin protesters. "We believe in Dharma. Right now, society is divided into two - Thaksin and the people. We have to choose a side, and we choose the people," he says.
Sunday's rally was the biggest so far in an opposition campaign that has filled the air with vicious jabs at Mr. Thaksin. Protesters accuse him of betrayal and cronyism over the $1.9 billion sale of his family's telecommunications company to Singaporean investors in January. Many also criticize free-trade talks with the US, which Thailand suspended last week because of the political impasse. In addition, opposition parties in parliament are boycotting the April 2 ballot, throwing the process into disarray. Thaksin says he won't surrender to "mob rule."