By Panarat Thepgumpanat and Panu Wongcha-um
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.
The stark choice comes 10 weeks after a March 24 election the opposition says was heavily weighted to favour pro-army parties.
Thailand's House of Representatives and the Senate will meet in a joint parliamentary session on Wednesday 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 be confirmed as prime minister thanks to the 250 votes of the Senate, which was wholly appointed by the junta.
However, the pro-military Palang Pracharat party that has nominated Prayuth does not have a majority in the elected lower house of parliament, the House of Representatives.
The party, which came second in the March 24 general election, already has more than a dozen coalition partners among small parties, the party leader Uttama Savanayana said on Tuesday.
But two major parties - the Democrats and Bhumjaithai - have yet to declare whether they will vote for either the pro-army alliance or the seven-party Democratic Front that seeks to curb the military's influence in politics.
"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.
(Editing by Robert Birsel)