Thailand’s constitutional court is set to decide the fate of prime minister Srettha Thavisin, in a ruling that could see him dismissed after less than a year in office and plunge the country into deeper political uncertainty.

Srettha, a real estate tycoon with no background in politics, is the subject of a complaint from ex-senators appointed by the former military government, who say he violated the constitution when he gave a cabinet post to a former lawyer who was once jailed.

If Srettha is removed, the 500-seat parliament must convene to choose a new prime minister, with the prospect of more upheaval in a country dogged for two decades by coups and court rulings that have brought down multiple governments and political parties.

The same court last week dissolved the anti-establishment Move Forward Party, the hugely popular opposition, ruling its campaign to reform a law against insulting the crown risked undermining the constitutional monarchy. It regrouped on Friday under a new party.

Srettha denies wrongdoing in appointing to cabinet lawyer Pichit Chuenban, who was briefly imprisoned for contempt of court in 2008 over an alleged attempt to bribe court staff, which was never proven.

“We’ve done our best and have submitted closing statements. I’ve set up plans based on the people’s needs and the care-taking PM can consider them,” Srettha said on the eve of the verdict, which will be delivered at 3pm local time.

The decision comes at a tricky time for Thailand’s economy, which Srettha has struggled to jumpstart. The government has estimated growth of just 2.7% for 2024, lagging regional peers, while Thailand has been Asia’s worst-performing market this year with its main stock index down about 17% year-to-date.

Deputy premier Phumtham Wechayachai would take over as caretaker if Srettha is removed. According to some political experts, it is likely Srettha’s party, Pheu Thai, would still have the clout to lead the next administration, after a period of uncertainty over who will be in charge.

“The government will still have 314 seats – the coalition remains united,” said Olarn Thinbangtieo, deputy dean of Burapha University’s faculty of political science and law.

“There may be some impact on confidence, but that would be in the short term.”

If Srettha is removed, those designated prime ministerial candidates by their parties before the last election can be nominated for premier.

They include Paetongtarn Shinawatra, Pheu Thai leader and daughter of influential billionaire Thaksin Shinawatra, former justice minister Chaikasem Nitisiri, interior minister and deputy premier Anutin Charnvirakul, energy minister Pirapan Salirathavibhaga and Prawit Wongsuwon, an influential former army chief who was involved in two coups.