Bangkok

THAILAND'S anti-military Democratic Front alliance will on Wednesday nominate rising political star Thana-thorn Juangroongruangkit for prime minister, facing off against junta leader Prayuth Chan-ocha, a spokeswoman said.

The scheduled vote for a new prime minister comes five years after then-army chief Prayuth seized power from an elected government in 2014.

Mr Thanathorn, leader of the opposition Future Forward Party, entered politics just last year and his party came in third in elections in March.

"The seven democratic parties coalition have jointly decided to nominate Thanathorn for the prime minister's vote," Pannika Wanich, spokeswoman for Future Forward, said.

Mr Thanathorn, 40, 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.

Wednesday's parliamentary vote for prime minister 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 that 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 Mr Prayuth, who took power in the 2014 coup.

Mr 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 Mr 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 if 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," Mr 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 has said that the appointed Senate's votes give Mr 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 Mr Prayuth as prime minister. REUTERS