The ruling also barred Move Forward’s charismatic, young former leader Pita Limjaroenrat and ten other prominent individuals from politics for ten years.
The Constitutional Court’s decision was expected, following its determination in January that Move Forward’s campaign promise to amend royal defamation rules was unconstitutional.
The court had ruled that modifications to the notoriously draconian lese majeste legislation were equal to calling for the demise of the constitutional monarchy.
Wednesday’s ruling serves as a harsh reminder of how far unelected institutions would go to maintain the monarchy’s power and status.
However, the verdict does not signal the end of the reforming movement in Thai politics.
The remaining 142 Move Forward MPs are anticipated to join another registered party and maintain their status as the biggest opposition in parliament.
This is essentially a replay of what happened in 2020, when the then-Future Forward Party, which had also performed unexpectedly well in an election, was disbanded and rebranded as the Move Forward Party.
That ruling four years ago sparked massive street protests spearheaded by a new generation of student activists, which lasted six months and included unprecedented demands for the monarchy to be held more accountable.
The government have made widespread use of the lese majeste law to prosecute.