The country has three leaders in a few days, following a court decision to suspend Paetongtarn Shinawatra.
Thailand led the appointment of the second interim prime minister this week following the suspension of the constitutional court of Paetong Tarun Sinawatra, the country’s leader, supported by telephone scandals with leading Cambodia politicians.
Home Minister Phumtham Wechayachai took on the responsibility of caretakers on Thursday, two days after Paetongtarn was banned from his duties, a government statement confirmed on Thursday.
In a social media post, the Thai government said the role of acting prime minister was agreed at the first meeting of the new cabinet, which took place shortly after the prime minister was sworn at the first meeting.
The 71-year-old will replace Suriya Jungrungreangkit.
The interim appointment was Hun Sen, an influential former leader in Cambodia.
The call came in mid-June with the aim of alleviating recent border tensions between the two countries following the eruption of violence that killed Cambodian soldiers.
Thai critics expressed anger at Paetong Tarn’s decision to call Hun Sen “uncle” and criticize the Thai Army commander.

The Constitutional Court has accepted petitions from 36 senators. This allegedly 38-year-old violated the constitution in his conversation with Hunsen.
It said that the “suspecting” Paetontarn violated the minister’s ethics and is currently investigating the case.
Before her halt began, Paetongaghn appointed herself as the new Cabinet Minister of Culture. She was sworn at the Great Palace on Thursday.
Paetongtarn’s government was struggling to revive the flag’s economy in a poll in late June.
The Thai political dynasty faces legal dangers on two fronts as another court hears a royal defamation lawsuit against her father, former Prime Minister Thaksin Sinawatra.
Thaksin denied the charges against him and repeatedly pledged his loyalty to the crown.
Thaksin avoided prison and spent six months in hospital custody on medical reasons before being released on parole last February. The Supreme Court will scrutinise his stay this month and potentially send him back to prison.
