(Bloomberg) -- Thai politician Pita Limjaroenrat faced his first major test in his bid to occupy the country’s top political office Thursday, as lawmakers gathered to elect a new prime minister in a vote that will test whether conservative groups are willing to undermine the results of a May election.

Pita, 42, was officially nominated for the job by Cholnan Srikaew, leader of Pheu Thai Party, the second-biggest outfit in Pita’s coalition that commands a total 312 lawmakers in the newly-elected 500-member House of Representatives. The National Assembly started casting their votes at 4:00 p.m. in Bangkok, after more than six hours of debates and speeches among its 750 members. 

Although the young reformist is the sole candidate running for the top job after his progressive Move Forward Party emerged as the biggest winner at the polls, there’s no guarantee he will win the premiership. 

He must first seek to win enough support from military-appointed senators to meet the threshold of 376 votes to become prime minister under electoral rules designed by the royalist establishment after a 2014 coup. On top of that, Pita also faces legal challenges that could see him disqualified as a lawmaker and his party disbanded over its push to amend the country’s royal defamation law. 

His disqualification would risk unleashing more protests, extending a decades-long political battle between conservative and democratic forces that has hit Thailand’s troubled stocks, bonds and currency markets. The nation’s benchmark stock index is the worst performer in Asia this year, and the baht is the second-biggest decliner in Southeast Asia since the May 14 vote. 

Thursday’s hours-long parliament meeting was dominated by debates surrounding Move Forward’s key platform vow to amend the lese majeste law, also known as Article 112 of the Thai criminal code that penalizes criticism of King Maha Vajiralongkorn and other royals. Challenges have been mounting for Pita, with conservative parties outside of the coalition and many members of the 250-member Senate, which is stacked with pro-royalist allies, ruling out support for Pita for this reason, even if he’s backed by the majority of the elected lower house.  

Still, the Harvard-educated politician said he sought to work together with lawmakers who opposed him but vowed to not soften the party’s stance. With the backing of a coalition of eight pro-democracy parties that swept the general election, Pita has to ensure the support of an additional 65 lawmakers — either from elected conservative politicians or the military-appointed upper house Senate — to hit the 376-vote mark to secure the premiership. 

“There are groups that want to block me from premiership and my coalition from forming a government. They’re using the monarchy to protect their interests and pitting the monarchy against the people’s votes on May 14,” Pita addressed lawmakers in a closing speech. “The politicization of the monarchy must end. We must find ways to improve and preserve the relationships between the king and the people in era of change.” 

READ: Thai PM Aspirant Risks Disqualification as Challenges Mount

Should he fail to win the required votes, though, he can seek a re-vote, with the next session likely to be held on July 19. 

As regards the case brought against him by the poll panel, Pita has said he didn’t own the shares but managed them as part of an estate left behind by his late father, and added that the shares have recently been transferred to a family member to avoid a plot to thwart his premiership bid. 

“In the short run, this development increases the likelihood that Pita will not have enough support in parliament,” said Napon Jatusripitak, visiting fellow at ISEAS-Yusof Ishak Institute. “In the long run, it raises concerns about the erosion of democratic principles and the potential for widespread protests.” 

READ: Latest Hurdle for Thai Election Winner Centers on Media Shares

Outside of the parliament complex, Pita’s supporters were gathering in orange-colored clothing — Move Forward’s distinctive color. Multiple protests were organized across the country on Wednesday following the Election Commission’s legal challenge. 

Pita has warned that efforts to thwart him will exact a heavy toll. 

The cases against Pita and Move Forward bear uncanny similarity to earlier ones against Thanathorn Juangrungruangkit, leader of Move Forward’s predecessor party. Thanathorn was found guilty by the same court for holding media shares and disqualified as a lawmaker. His party, known as Future Forward, was later dissolved in another case, igniting a mass protest movement in 2020 that led to unprecedented calls for monarchy reforms.

--With assistance from Suttinee Yuvejwattana, Napat Kongsawad and Pathom Sangwongwanich.

(Updates with details of voting in the second paragraph.)

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