Battery of legal woes threatens electoral success of popular politician seen as threat to ruling military bloc.

The popular leader of Thailand’s anti-military parliamentary bloc appeared in court on Friday on the charge of breaching election rules by owning media shares, a case which could see him barred from politics and jailed for up to 10 years.

Billionaire Thanathorn Juangroongruangkit, 40, has rattled the kingdom’s establishment since seizing the political limelight with his criticisms of the army’s role in Thai politics and society, and vision for the country’s future.

His Future Forward Party (FFP) energised voters and became the third-largest political group in Thailand in a March election which ended five years of outright military government rule.

The party was backed by millions of young people wearied by the dominance of the conservative old guard.

But Thanathorn’s electoral success has been matched by a battery of legal woes.

He has been suspended from parliament since the Election Commission accused him of breaking polling laws by holding media shares – an offence that carries a long jail term.

Arriving for the first hearing at the Constitutional Court on Friday, Thanathorn again pleaded his innocence telling reporters the media company had ceased operations five months before the election.

“We are convinced that there is no evidence,” he said.

His supporters say the case has been trumped up to take out Thailand’s most popular politician and deliver a major blow to the FFP and its radical reform agenda.

The party wants to amend the constitution to excise the military’s influence, slash defence spending and end conscription to an army that has carried out a coup at an average of once every seven years since the establishment of a constitutional monarchy in 1932.

“The party is against the military … I support their vision and I absolutely support Mr Thanathorn,” Punjarat Wattawongvibul, 35, told AFP news agency outside the court.

The highly-interventionist court disbanded a different anti-military opposition party linked to former premier Thaksin Shinawatra just before the March election.

Thanathorn has also been singled out by the kingdom’s powerful army chief.

General Apirat Kongsompong last week delivered a diatribe warning of the spectre of a communist rebellion in a speech peppered with barely-concealed references to Thanathorn and his party.

FFP has been a rare voice of criticism against Thailand’s royalist establishment.

The monarchy, one of the world’s richest and headed by King Maha Vajiralongkorn, is at the apex of Thai power.

On Thursday, 70 FFP MPs voted against a royal decree transferring two key army units to the direct control of the king – an unprecedented political objection to a royal command.

The decree was still approved in parliament with an overwhelming majority.