Thailand's former prime minister Thaksin Shinawatra smiles as he walks out from a beauty salon in Bangkok on June 5, 2024.

Former Thai Prime Minister Thaksin Shinawatra was formally charged with royal insult on Tuesday, marking another development in a series of legal cases that threaten to destabilize the Southeast Asian nation politically. 

Thaksin, who has served as Prime Minister twice and is the de facto leader of the ruling Pheu Thai party, was arraigned under Thailand’s strict lèse-majesté law, which protects the royal family from criticism, according to a spokesperson from the attorney general’s office.

While the outcome of the case remains uncertain, the legal proceedings pose risks to the less than year-old government formed after a contentious general election last year. They also signal a potential unraveling of the agreement that brought together Pheu Thai and a group of pro-royalist and military-aligned parties to form a government, paving the way for Thaksin’s return.

The charges against Thaksin, 74, stem from a 2015 interview he gave in Seoul that prosecutors believe violated Article 112 of Thailand’s penal code, which carries a maximum sentence of 15 years for each offense of defaming the monarchy.

The attorney general last month decided to indict Thaksin, stating that sufficient evidence existed to proceed with a trial. Thaksin has denied the charges, and his lawyer has vowed to contest the case in court. 

“The case is baseless — it’s fruit from a toxic tree,” Thaksin told reporters on June 8, in his first public remarks concerning his legal troubles, which stem from comments he made in 2015 following the military takeover. “It’s an example that shows how charges are abused after a coup.”

Thailand’s Constitutional Court is also scheduled to resume deliberations on a case seeking Prime Minister Srettha Thavisin’s removal from office due to alleged ethical violations in appointing a lawyer who served prison time as a cabinet minister.

The increasing political uncertainty has shaken Thailand’s financial markets, leading foreign investors to withdraw more than $3 billion from the nation’s stocks and bonds. The benchmark SET Index of stocks has plummeted to a near four-year low, making it the worst-performing among all global stock exchanges tracked by Bloomberg in the past year, while the baht has become Asia’s worst-performing currency after the Japanese yen this year.