Thailand’s Constitutional Court on Wednesday ordered the dissolution of the nation’s largest opposition party after finding it guilty of breaching election rules with its campaign to amend a stringent royal defamation law.

In a unanimous ruling, the nine-member court found that Move Forward’s bid to amend the lese majeste law, also known as Article 112 of the Thai penal code, violated the poll rules. The court also banned its leaders, including its prime ministerial candidate Pita Limjaroenrat, from political activities or running for public office for 10 years.

Under Thai election rules, about 150 Move Forward lawmakers in the 500-member House of Representatives must now move to a new party within 60 days.