BANGKOK (Reuters) - Thailand’s parliamentary vote for prime minister on Wednesday will be a contest between the leader of a 2014 military coup and a rising opposition star facing two criminal charges he says stem from his stand against the junta.

FILE PHOTO: Thanathorn Juangroongruangkit, leader of the Future Forward Party attends a news conference to form a "democratic front" in Bangkok, Thailand, March 27, 2019. REUTERS/Soe Zeya Tun

The stark choice comes 10 weeks after a March 24 general election the opposition says was heavily weighted to favour pro-army parties.

The House of Representatives and the Senate are due to meet in a joint session to vote for a prime minister and officially restore civilian rule after more than five years of military government under Prayuth who took power in the 2014 coup.

Prayuth looks likely to have enough support to win and stay on as prime minister thanks to the 250 votes of the Senate, which was wholly appointed by the junta.

The pro-military Palang Pracharat party that nominated Prayuth and came second in the March 24 election has now formed alliances with more than a dozen partners, the party leader Uttama Savanayana said.

The pro-establishment Democrat Party became the latest major party to join the Palang Pracharat-led coalition late on Tuesday, likely also giving the pro-military camp a slim majority in the elected House of Representatives.

“Everyone wants the government to be formed quickly. Those who are working to form the cabinet must find a way to create a stable government,” Prayuth said.

“This will not be a government of just any one party. There must be a way and the people are hopeful about the government,” he said.

The Democratic Front will nominate upstart political star Thanathorn Juangroongruangkit of the new Future Forward Party for prime minister to face off against Prayuth, a spokeswoman said.

Thanathorn, 40, entered politics just last year and his party third in the March election.

“The seven democratic parties’ coalition has jointly decided to nominate Thanathorn for the prime minister’s vote tomorrow,” Pannika Wanich, spokeswoman for Future Forward, told Reuters.

Thanathorn faces at least two criminal charges of sedition and cybercrime for allegedly aiding anti-junta protesters shortly after the coup and for a critical speech on Facebook - charges he has characterised as politically motivated.

The Democratic Front has said that the appointed Senate’s votes give Prayuth an unfair advantage and also complained after the Election Commission changed a seat-allocation formula after the March vote to give 10 small parties one seat each, mostly at the expense of Future Forward.

The 10 parties have since all joined the alliance to keep Prayuth as prime minister.