Thai Prime Minister Ousted Over Leaked Phone Call

The move by Thailand’s Constitutional Court injects more uncertainty into the country’s turbulent domestic politics.

Thailand’s Constitutional Court on Friday removed Prime Minister Paetongtarn Shinawatra citing serious ethical breaches related to a phone call this summer with the former strongman of neighboring Cambodia.

Thailand's Paetongtarn Shinawatra, who was dismissed as prime minister, looks out of a vehicle as she leaves the Government House, after the Constitutional Court ruled to remove her from office in a high-profile ethics case, (REUTERS)

The court had already suspended Paetongtarn last month after a group of senators lodged a complaint with the court over her conversation with Hun Sen, Cambodia’s longtime leader and the father of the country’s former prime minister. During that call to discuss an escalating border dispute between the two countries, Paetongtarn appeared submissive, referring to Hun Sen as “uncle” and to Thailand’s powerful military as the “opposing side.”

Hun Sen later released a recording of the call, setting off a political crisis in Thailand just as the border dispute turned into a full-blown military confrontation.

In her defense to the court earlier this month, Paetongtarn—the daughter of Thailand’s veteran political leader and telecoms tycoon Thaksin Shinawatra—presented her language during the call as a negotiation tactic aimed at de-escalating the border issues. “Throughout the entire conversation, my intention was solely to safeguard the national interest, without any aim of securing personal benefit,” she said.

Friday’s ruling is the latest blow to the Shinawatra dynasty and the broader political movement founded by her father. Paetongtarn is the third member of her family removed as prime minister before the end of their term, following in the footsteps of her father, who was ousted in a 2006 coup, and her aunt, Yingluck Shinawatra, whom the Constitutional Court found guilty of abusing her power. Three other prime ministers belonging to political parties linked to Thaksin Shinawatra have also been ousted by the court since 2008.

Paetongtarn could face further penalties, including a lengthy prison term, from a separate investigation into the phone call with Hun Sen by Thailand’s antigraft body.

The Constitutional Court’s verdict injects more uncertainty into Thailand’s already turbulent domestic politics. Paetongtarn’s governing coalition depends on a thin parliamentary majority that could struggle to elect a new prime minister. At the same time, it is unclear if acting Prime Minister Phumtham Wechayachai has the power to call a new election, which would likely see Paetongtarn’s Pheu Thai Party lose more votes.

The ruling also raises bigger questions about Thailand’s political system and the power held by establishment institutions such as the monarchy, the military and the bureaucracy. “How come a democratically elected prime minister keeps being suspended or removed or overthrown in a military coup?” said Thitinan Pongsudhirak, a professor of international relations at Thailand’s Chulalongkorn University. “This is the question that is facing Thailand. It’s not just the Shinawatra family.”

Write to Gabriele Steinhauser at Gabriele.Steinhauser@wsj.com