Thailand’s constitutional court on Thursday ruled to dissolve one of country’s main opposition parties, dealing a crushing blow against the democratic movement contesting a March 24 election.

The verdict to disband the Thai Raksa Chart party means that its executives will be banished from politics for at least 10 years and its 251 candidates will be disqualified from campaigning or standing in the upcoming poll.

The nine judges voted unanimously to dissolve the party and were divided six to three on imposing a ban on the executive members.

Thai Raksa Chart, aligned to the Pheu Thai party of exiled former Prime Minister Thaksin Shinawatra, landed itself in a legal minefield last month when it nominated the king’s sister, Princess Ubolratana Rajakanya as its prime ministerial candidate.

The selection of the princess caused uproar in the southeast Asian nation, where the royal family is revered and strictly enforced lese-majeste laws make it a criminal offence to insult the monarchy.