Court says Thanathorn Juangroongruangkit cannot take seat in parliament while it considers case against him.

A court in Thailand has blocked the leader of a new anti-military-government political party from taking his seat in parliament while it considers allegations he violated election rules, in a move likely to increase political tension in the Southeast Asian nation.

Thanathorn Juangroongruangkit, the multimillionaire leader of Future Forward, which stormed to third place in the March 24 elections, is accused of breaking electoral law by holding shares in a media company.

In a statement on Thursday, the Constitutional Court said it had decided to “accept the petition to rule on the case and will notify the accused”, adding that Thanathorn’s status as a member of parliament was suspended until the verdict.

It did not give a date for the ruling.

Thailand’s parliament is due to convene on Friday for the first time since the elections, with the military-backed party of Prayuth Chan-ocha who led the military coup five years ago trying to form a government against a rival coalition that includes Future Forward.

A vote on the lower house speaker will take place on Saturday and a prime minister could be chosen as early as next week.

‘Fight together’

Thanathorn, who had earlier offered himself as a prime minister candidate for the anti-military coalition, denies the charges.

The 40-year-old says the shares were divested weeks before he registered to run and has called the legal assaults political sabotage.

“I ask people who love justice to stand up and fight together,” he said at his party headquarters after the court announcement, as supporters shouted “Fight Thanathorn!”

The Constitutional Court, which in February dissolved another opposing the military government, could ban Thanathorn from politics, impose a jail sentence and dissolve Future Forward.

Thanathorn also faces a sedition charge with a potential seven-year jail sentence and additional allegations that he violated the draconian Computer Crime Act with a Facebook live speech in which he criticised the military government. A decision on whether to proceed with the latter is scheduled for next week.

Future Forward, which wants the armed forces out of politics, stunned the Thai establishment by securing more than six million votes in the polls and 80 seats in parliament.

It found support among Thais weary of the divide between supporters of exiled tycoon Thaksin Shinawatra and the traditional and military elite that has dominated the country’s politics for some two decades.

March’s poll was the first since Prayuth seized power in 2014, but it took place under a new constitution and voting system that ensured the military the upper hand.