The biggest party in Thailand’s caretaker government will meet on Thursday to choose a successor for dismissed former premier Srettha Thavisin, as it races to shore up its alliance a day ahead of a pivotal parliamentary vote on a new prime minister.

Thailand is again gripped by political drama, less than a year after real estate mogul Srettha rose to power after weeks of parliamentary deadlock, with his Pheu Thai party scrambling to retain control and deliver on its stalled populist agenda amid a struggling economy.

The constitutional court’s dismissal of Srettha on Wednesday was the latest hammer blow for Pheu Thai, the electoral juggernaut of the billionaire Shinawatra family that has locked horns for two decades with Thailand’s influential establishment and royalist military.

Earlier this month, Thailand’s constitutional court ordered the dissolution of Move Forward, the country’s most popular party, and banned its leaders from politics for 10 years, over its election promise to reform the country’s strict lese-majesty law.

Pheu Thai must now choose one of two eligible candidates – Chaikasem Nitisiri, a former attorney-general and justice minister, and its inexperienced leader Paetongtarn Shinawatra, the 37-year-old daughter of divisive political heavyweight Thaksin Shinawatra.

Srettha was the movement’s fourth premier to be removed by a court ruling, and his downfall could indicate the end of an uneasy detente between Thaksin and his enemies in the conservative elite and military old guard, which had enabled the tycoon’s return from self-exile in 2023 and ally Srettha to become premier the same day.

Pheu Thai has moved quickly to preserve its advantage, with media broadcasting live images late on Wednesday of its coalition partners visiting the residence of Thaksin, 75, its founder and influential figurehead.

“They want to be decisive … The longer it takes, the more squabbles and power struggles will ensue, so the quicker the better,” said Thitinan Pongsudhirak, a political scientist at Chulalongkorn University.

“If they can vote sooner, then the vote is more manageable. They can control the outcome of the house.”

The court ruled Srettha had “grossly breached ethical standards” when he gave a cabinet post to Thaksin’s former 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.

The convening of parliament less than 48 hours after Srettha’s dismissal contrasts sharply with last year, when it took two months for the lower house to sit to vote on a new premier after an election.

Lawmakers allied with the military had then closed ranks to block the anti-establishment election winner Move Forward from forming a government, but rallied behind Srettha and Pheu Thai in a second vote six weeks later.

The 11-party Pheu Thai alliance holds 314 house seats and should have no difficulty electing a prime minister on Friday, providing it remains intact.

To become premier a candidate needs the approval of more than half of the current 493 lawmakers.

Pheu Thai must decide whether to go with party stalwart Chaikasem, or give a baptism of fire to neophyte Paetongtarn, and risk the kind of backlash that saw her father, and then her aunt Yingluck Shinawatra, both toppled in coups before fleeing into exile to avoid jail.

“If it’s Paetongtarn, she would be open to attack … If you ask Thaksin, he probably wants her to be prime minister,” said Titipol Phakdeewanich, a political scientist at Ubon Ratchathani University.

“If Pheu Thai can’t deliver anything then it could be the end of the Shinawatra family in politics.”