Thailand's Constitutional Court agreed Wednesday to hear a case accusing the prime minister frontrunner, Pita Limjaroenrat, of attempting to overthrow the monarchy.

The decision comes on the same day that another unrelated case was submitted against him.

The court statement says the case alleges that Pita and his progressive Move Forward Party promising on the campaign trail to amend the royal defamation law amounts to attempting to "overthrow" the constitutional monarchy.

Thailand’s Election Commission said Wednesday it concluded there is evidence that the top candidate to become the country’s next prime minister, a reformist with strong backing among progressive young voters, violated election law and referred his case to the Constitutional Court for a ruling.

The commission’s decision included a request that the court order Move Forward Party leader Pita Limjaroenrat suspended as a member of Parliament until the ruling is issued. Thai media reported that the court would not make any ruling on Wednesday and indicated that it might need some time to consider the issue.

Pita can still be nominated on Thursday when Parliament meets to vote for a new prime minister. But the commission's move raises new doubts about whether he can muster enough votes to get the post, already a struggle because of Thailand's deep political divisions.

The Move Forward Party, with a progressive reformist platform, swept to a surprise first-place finish in May’s general election, capturing 151 seats in the 500-member House of Representatives and the most popular votes.

Move Forward has assembled an eight-party, 312-seat coalition it had planned to take power. But the unlikely approval from members in the conservative 250-seat non-elected Senate, which participates in the vote for prime minister, makes Pita’s path to power a difficult one.

Pita's party responded to the commission's decision by questioning its fairness and even its legality. It said its decision was unnecessarily hurried and violated its own procedures by failing to call Pita to give a statement.

The commission had earlier said it acted correctly but Move Forward alleges it may have violated the law on malfeasance, which makes an official who carries out his duties in a wrongful manner or fails to carry out his lawful duties, subject to criminal punishment of one to 10 years imprisonment and a fine.

The case against Pita hinges on his alleged ownership of shares in a media company, which would bar him from running for office. The complaint against him, lodged by a member of a rival political party, applied to the period of the 2019 general election. Pita had challenged the basis for the claim, which extended to his failure to include the shares on a mandatory assets declaration.

The case the commission referred to the court goes beyond a technical election law violation and accuses Pita of running for office with the awareness that he was ineligible, a criminal violation is punishable by a maximum imprisonment of three years and/or a fine of up to 60,000 baht ($1,720). The party faces a fine of up to 100,000 baht.

Caretaker Deputy Prime Minister Wissanu Krea-ngam, the government’s top legal advisor, has been quoted as saying that if party leader Pita was ruled unqualified to endorse his party’s candidates for the May election, the polls could be nullified and a new election called.

There have been fears since the election that Thailand’s conservative ruling establishment would use what its political opponents consider to be dirty tricks to hold on to power.

For a decade-and-a-half, it has repeatedly used the courts and so-called independent state agencies such as the Election Commission to issue controversial rulings to cripple or sink political opponents.

The dissolution in 2019 of the Future Forward party, a forerunner of Move Forward, triggered vigorous street protests by pro-democracy activists that trailed off only when the coronavirus pandemic took hold.