BANGKOK (REUTERS) - Thailand's Constitutional Court ruled on Tuesday (Jan 21) that key figures of the opposition Future Forward Party were not guilty of opposing the monarchy, an allegation that could have seen the high-profile party banned in one of several ongoing cases against it.

The verdict means the party will not be dissolved in one of several legal cases it faces.

The ruling was a relief for the opposition, which has said the anti-monarchy charges were politically motivated to suppress dissent against Thailand's government headed by a former military junta leader.

The court rejected the claims the party sought to overthrow Thailand's monarchy.

The complaint also alleged the party is linked to the Illuminati, a secret society that conspiracy theorists believe seeks world domination.

"The accused have not acted in their rights and liberties to overthrow the constitutional monarchy," said Mr Taweekiat Meenakanit, one of the judges.

But Mr Taweekiat noted that the party should revise wording in its manifesto, which states that it abides by "democratic principle per the Constitution", to say "democratic system with the king as head of state".

King Maha Vajiralongkorn, 67, is a constitutional monarch, but in traditional culture, the monarch is revered as the country's protector and insulting the king is a criminal offence punishable by up to 15 years in prison.

Seeking to abolish the monarchy is considered a grave offence.

Founded almost two years ago, Future Forward Party came third in last year's general election, which the opposition says was manipulated in favour of the pro-military Palang Pracharat Party.

Its leader Thanathorn Juangroongruangkit, 41, has emerged as the most prominent opponent to the government that last year reinstalled former junta leader Prayuth Chan-o-cha, 65, as a civilian prime minister five years after he staged a military coup.

At the party's headquarters in Bangkok, supporters broke into cheers after the verdict was delivered.

"This should not have been a case in the first place. I would like to stress that neither Thanathorn, myself, nor the party, want to undermine the constitutional monarchy," said Mr Piyabutr Saengkanokkul, the party's secretary-general.

But analysts said Future Forward could still be dissolved on one of the other legal cases it faces.

One case alleges that Future Forward violated electoral laws governing by accepting loans from party leader, auto-parts billionaire Thanathorn.

"The bottom line is Future Forward's days are numbered," said Mr Thitinan Pongsudhirak, a political analyst at Chulalongkorn University.

"Because they stand against the military junta, stand for reforms and a new kind of Thailand that the conservative establishment won't accept."