Former prime minister Srettha Thavisin reacts after Thailand's Constitutional Court ruled to remove him
Former prime minister Srettha Thavisin reacts after Thailand's Constitutional Court ruled to remove him AFP

The party of Thailand's billionaire ex-PM Thaksin Shinawatra meets on Thursday to choose a candidate for prime minister, a day after the kingdom's top court dismissed incumbent premier Srettha Thavisin over an ethics violation.

The Constitutional Court on Wednesday ruled that Srettha, 62, had breached regulations by appointing a cabinet minister with a criminal conviction, deepening Thailand's political uncertainty a week after the dissolution of the main opposition party.

Parliament is scheduled to meet at 10:00 am (0300 GMT) on Friday to vote on a new PM.

Srettha's Pheu Thai party -- the electoral vehicle of one-time Manchester City owner Thaksin -- is the largest member of a governing coalition of 11 parties that includes royalist and pro-military outfits who were once its bitter rivals.

On Thursday the party will choose one of its two eligible candidates -- former justice minister Chaikasem Nitisiri, or Thaksin's daughter Paetongtarn Shinawatra -- as a replacement for Srettha.

Pheu Thai secretary-general Sorawong Thienthong told reporters they would discuss their choice with coalition partners.

Srettha is the party's third prime minister to be kicked out by the Constitutional Court, and is leaving office after less than a year.

Thai politics has endured two decades of chronic instability marked by coups, street protests and court orders -- much of it fuelled by the long-running battle by the military and pro-royalist establishment against progressive parties linked to their bete noire Thaksin.

The tycoon ex-premier returned to Thailand last August from 15 years in self-exile on the same day Srettha took power in an alliance with pro-military parties previously staunchly opposed to Thaksin and his followers.

The timing seemed to suggest a truce in the long-standing feud as both sides sought to see off the threat posed by the newer Move Forward Party (MFP), which won the popular vote in last year's election only to be blocked from forming a government.

The case against Srettha was brought by 40 former senators appointed by the military junta that ousted an elected Pheu Thai government in a 2014 coup.

The senate also played a crucial role in blocking the MFP after last year's elections.

Senators alarmed by MFP's pledges to reform lese-majeste laws and break up powerful business monopolies refused to endorse its then-leader Pita Limjaroenrat as prime minister, and the party was forced into opposition.

The top court last week dissolved the MFP and banned Pita and its main officials from politics for 10 years.

Srettha, meanwhile, was dismissed over the appointment of Pichit Chuenban, a former lawyer associated with Thaksin.

Pichit, sentenced to six months in jail in 2008 for a graft-related offence, quit the cabinet after the case was filed in a bid to save Srettha, but the court pressed ahead with the case.