April 6 (UPI) -- Thailand's military junta filed a sedition charge Saturday against a 40-year-old progressive party leader.
The sedition charge is among three that Thanathorn Juangroongruangkit faces in connection with a pro-democracy rally he attended four years ago.
Since the sedition charge relates to national security, he will be tried in military court, which Thanathorn said he was slightly worried about.
Thanathorn also faces a charge of helping a suspect escape and a charge of assembling of more than 10 causing unrest. If convicted of all charges, he could serve up to nine years in prison, including seven years for the sedition charge alone.
The junta, called the National Council for Peace and Order, has ruled Thailand since a 2014 military coup forced the democratically elected government out.
Police allege Thanathorn "provided assistance" to a leader of demonstrators against the coup who violated the junta's ban on gatherings of more than five people.
Thanathorn, the billionaire leader of the youth-backed Future Forward Party, which he formed last year, said the complaint's timing, after his party tentatively came in third with 6.3 million votes in last month's contested elections, was not coincidental.
"We're convinced that this case is politically motivated," Thanathorn said.
The March 24 election was Thailand's first election in eight years and showed inconclusive results. With more than 90 percent of the vote counted, the pro-military party led with 7.59 million votes, and the populist party trailed closely behind with 7.12 million votes, and the FFP came in third.
Thanathorn's progressive policy ideas and use of social media has attracted youth to his campaign.
He has denied the charges and has a May 15 deadline to give written testimony to police.
He also faces a separate cybercrime charge over criticizing the Junta on Facebook in July.
Thanathorn has denied the charge.
Prosecutors will decide on April 26 whether he will face trial for the cybercrime charge.