Sorawong Thienthong, secretary-general of Pheu Thai, told reporters at Parliament on Thursday that the party executives are meeting later in the day to decide on its prime ministerial nomination in Parliament, with a vote scheduled for Friday.

Pheu Thai's Srettha was ousted on Wednesday after less than a year in office. The Constitutional Court found him guilty of a serious ethical breach regarding his appointment of a Cabinet member who was jailed in connection with an alleged bribery attempt.

It was the second major ruling in a week to shake Thai politics. The same court last week dissolved the progressive and main opposition Move Forward party, which won last year's general election but was blocked from power, saying it violated the Constitution by proposing an amendment to a law against defaming the country's royal family. The party has already regrouped as the People's Party.

Pheu Thai's ruling coalition partners have already given their endorsement for the party's candidate, including the Bhumjaithai party, which came third in the election, and the pro-military Phalang Pracharath and United Thai Nation parties.

Anutin Charnvirakul, the Bhumjaithai party's candidate and leader is seen as another frontrunner, though he said he would not contest Friday's vote against a candidate from Pheu Thai.

Pheu Thai has two eligible candidates that were put up for the general election in 2023. One is Paetongtarn Shinawatra, the daughter of former Prime Minister Thaksin Shinawatra who is seen as a real patriarch behind Pheu Thai. Another is Chaikasem Nitisiri, 75, a former Minister of Justice who served in the Pheu Thai government led by Thaksin's sister Yingluck Shinawatra and was removed by a coup in 2014.

Pheu Thai finished second in last year's election but was given a chance to form a government after the winners, reformist Move Forward party, was blocked from taking power by the previous Senate, a military-appointed body.

Move Forward was then excluded from the coalition by Pheu Thai, who went on to join hands with parties affiliated with the previous military-backed government that ousted it in a coup. The move drew criticism from some of its supporters but party officials say that it was necessary to break the deadlock and start reconciliation after decades of deep political divisions.

The former senators were given special power to veto a prime ministerial candidate by the constitution adopted in 2017 under a military government. That power expired when their term ended in May, however. New members of the Senate, selected in a convoluted process last month, do not retain the veto.

A candidate now needs just a majority from the lower house, or at least 247 votes. The House of Representatives now has 493 sitting members after six were banned from politics as a result of Move Forward's dissolution. Another lawmaker of the Bhumjaithai party is suspended awaiting a court ruling.

While Pheu Thai's key coalition partners endorsed its candidate, all of them reiterated that they would not support a proposal to amend the royal defamation law which became a key issue during last year's election. Pheu Thai discussed the issue during the election campaign but has toned down significantly after becoming the government.

The law, also known as Article 112 in Thailand's criminal codes, protects the monarchy from criticism with penalties of up to 15 years in jail per offense. Critics say the law is often wielded as a tool to quash political dissent.

The People's Party, new home for lawmakers of the dissolved Move Forward, said Thursday that it will not vote to approve a candidate from Pheu Thai on Friday. Party leader Natthaphong Ruengpanyawut said the party will continue its duty as an opposition.