Thailand’s leading pro-democracy party, which swept Sunday’s election, is confident its coalition will win over senators’ prime ministerial votes for its leader Pita Limjaroenrat.

The Move Forward party has been in contact with senators to assess their opinions and concerns, Chaithawat Tulathon, the party’s secretary general, said in a statement Saturday. Some senators are set to hold informal meetings on May 23 to discuss their votes for the new prime minister, he said.

While Pita’s party secured a historic win in the election, it faces built-in obstacles to forming a government. Move Forward and its coalition partners have about 313 votes in the 500-member House of Representatives, but it needs the backing of at least 376 lawmakers in a joint sitting of the lower house and the Senate that will select the new prime minister. The Senate has 250 members.

“I am confident that some senators will have a better understanding of our policies after seeing the memorandum of understanding that will be endorsed by all coalition parties on Monday,” Chaithawat said. “This would help those senators make constructive decisions that will propel our country forward.”

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Harvard-educated Pita’s bid for the top job has faced challenges including opposition from a majority of the Senate, stacked with allies of the pro-military establishment of incumbent Prime Minister Prayuth Chan-Ocha, and other conservative parties. Bhumjaithai, the party that came third with 70 seats, ruled out its support for Pita, saying it won’t back a candidate seeking to amend the law that mandates as many as 15 years in jail for insulting top royals including King Maha Vajiralongkorn.

While Move Forward has pledged to amend the so-called lese majeste law, its coalition partner Pheu Thai has maintained that the issue should be settled in parliament.

The coalition parties are set to sign a pact to outline their policies and frameworks for the new government on Monday. Pheu Thai on Friday urged Move Forward to rethink its intention to include a proposal amending the lese majeste law in an agreement that it is asking prospective coalition partners to sign, the Bangkok Post reported.

In a separate statement, Move Forward apologized to its supporters for a plan to invite the small Chartpattanakla party to join its coalition. The planned invitation had caused a backlash among Move Forward supporters because Chartpattanakla’s leader Korn Chatikavanij is a former lawmaker who voted to keep then-junta leader Prayuth in power after a 2019 election.

--With assistance from Patpicha Tanakasempipat.