BANGKOK: Thai prime ministerial hopeful Pita Limjaroenrat was dealt a major setback on Wednesday when two separate complaints against him gained momentum, threatening to derail his leadership bid on the eve of a crucial vote on the premiership.

Pita's supporters, many of them younger voters opposed to the royalist military's involvement in politics, called for protests later on Wednesday, raising the possibility of another round of turmoil in two decades of fractious Thai politics.

The Constitutional Court said it had accepted a complaint filed by a lawyer against Pita and his election-winning Move Forward Party's that said its plan to reform a law prohibiting royal insults amounted to an attempt "to overthrow the democratic regime of government with the king as a head of state".

It came just hours after the election commission recommended that the same court disqualify Pita as a lawmaker, saying it found merit in a complaint alleging he was unqualified to run in the May 14 general election, because of his ownership of shares in a media company in violation of electoral rules.

There was no immediate indication either development would prevent Pita, 42, from contesting Thursday's vote, where he faces a challenge to win the required backing of more than half of the legislature.

To gather enough support in parliament to become prime minister it looks as if Pita must win over conservative members of a Senate opposed to his party's anti-establishment agenda, its most contentious element being amending article 112 of the criminal code, which punishes insults of the crown by up to 15 years in jail.

Pita said the electoral commission's recommendation that he be disqualified was unfair and he questioned the timing.

"This is a bit rushed, one day before the PM vote, it shouldn't have happened," he told reporters.

In a television interview as the court announced the new case, Pita stressed that his party's proposal to amend article 112 was not an attempt to undermine the monarchy.

Buoyed by massive support from young voters for its bold reform plans, Move Forward and another opposition party thumped rivals allied with the royalist army in the May election in what was widely seen as an overwhelming public rejection of nine years of government led or backed by the military.

Move Forward beat the populist Pheu Thai party, that had been expected to win, by 10 seats and the two parties together hope to form a coalition government after Thursday's vote.

'FIGHT HAS BEGUN'

The court cases are the latest twist in a turbulent, two-decade battle for power in Thailand that broadly pits conservatives allied with the royalist military and influential old money families against parties elected on populist or progressive platforms.

Leaders of a student-led protest movement that had called for reform of article 112 and held massive rallies against the outgoing military-backed government urged its supporters to take to the streets later on Wednesday in at least five cities, including Bangkok.

"There must be a retaliation to the effort to destroy democracy," protest leader Anon Nampa said in a hand-written note posted on Twitter.

"Whatever the conclusion, let all know that the fight has begun."

Pita, a U.S.-educated former executive of ride-hailing app Grab GRAB.O, is backed by an eight-party alliance that controls 312 of the seats in the lower house of parliament.

He is expected to run unopposed on Thursday but still needs 64 more votes, either from rival parties in the lower house or the junta-appointed Senate, a challenge that could now be even more difficult.

In another setback, Democrat Party politician Chaichana Dechdecho told Reuters his party's 25 lawmakers would not back Pita in Thursday's vote because of his party's plans to amend 112.

Senator Jetn Sirathranon told Reuters the commission's recommendation that Pita be disqualified would undermine support for him.

"A prime minister of Thailand has to be dignified and untarnished," he said.



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