After his election as the country’s 30th prime minister, Srettha said he would do his best and “work tirelessly to improve the quality of life for the Thai people”. The Pheu Thai candidate had previously easily secured the required majority in the lower house and among the senators appointed by the military junta. He was confirmed in office with 482 yes votes, far more than the required 374 votes.

The Pheu Thai-led coalition took over the task of forming a government after senators blocked the actual winner of May’s general election, Pita Limjaroenrat and his progressive MFP party.

The Pheu Thai alliance is controversial because it also includes parties close to the army. This fueled speculation that Pheu Thai had struck a deal with the military junta in exchange for Thaksin being pardoned, which the party denies.

The 74-year-old Thaksin landed in a private jet at Don Mueang Airport in Bangkok on Tuesday morning after 15 years in self-imposed exile, where he was greeted by hundreds of supporters. He was then taken to the Supreme Court, where the eight-year sentence imposed in his absence was ordered. Thaksin was convicted on three counts, including one related to his former company, Shin Corp.

The Correctional Authority said Thaksin was isolated in prison because of health problems including heart and lung problems. His family will be able to visit him after five days.

Thaksin considers the criminal proceedings to be politically motivated. An opponent of Thailand’s pro-military and royalist establishment, the media magnate who ruled the country from 2001 to 2006 and was then overthrown by the military still wields great influence over politics in the kingdom.

As of 2008, Thaksin lived in exile, most of it in Dubai. Despite his long absence, Thaksin remains the most influential and controversial politician in Thailand. He has been polarizing the country with his supporters of the “red shirts” versus the “yellow shirts” (monarchists) for over twenty years.

When asked about a possible royal pardon for Thaksin, the Correctional Authority said the process would take “about a month or two if the documents are sufficient.” Important parties to the proceedings could apply for the royal pardon process.

According to Southeast Asian politics expert Aaron Connelly, Pheu Thai anticipates such a trial. If Thaksin is not pardoned by the king within a certain period of time, the party may question whether it formed a coalition under false pretenses, he told AFP.