Thailand's progressive Move Forward Party, which won most seats at the last election, was Wednesday ordered to stop campaigning to reform the kingdom's tough royal defamation laws, as a top court ruled the policy was unlawful.
MFP upended Thailand's political order by coming first in the general election last May, but its promises to reform the military, business monopolies and lese-majeste laws spooked the kingdom's powerful conservative elite.
Then-leader Pita Limjaroenrat was blocked from becoming prime minister and MFP was shut out of the governing coalition.
The Constitutional Court on Wednesday ruled that the party's campaign pledge to reform Thailand's strict laws protecting King Maha Vajiralongkorn amounted to an attempt to "overthrow the monarchy".
The court said the plan to amend the royal defamation law showed "an intent to separate the monarchy from the Thai nation, which is significantly dangerous to the security of the state".
"There are prohibitions on the exercise of rights and freedoms that affect the country's security and peace, order of the state, and good morals," it said.
The court ordered Pita and MFP to stop campaigning for lese-majeste reform immediately.
Pita -- who stepped down as party leader last year -- returned to parliament last week after the same court cleared him of breaching election laws in a case that could have seen him barred from politics.
Thanathorn Juangroongruangkit, the former leader of Future Forward Party -- an MFP forerunner dissolved by court order -- said before the ruling that lese-majeste should be up for discussion.
"The law is not a fax paper sent from God. It's written by human hands, therefore people can amend it," Thanathorn told reporters on Wednesday.
"If the lawmakers cannot amend the laws, I think something is wrong in the country."
The lese-majeste law is intended to protect the king -- a revered, semi-divine figure in Thai society -- from insult, and those breaking it can face up to 15 years in jail per offence.
But critics say the legislation has been interpreted so broadly in recent years as to shield the royal family from any kind of criticism or mockery.
This month, a man was sentenced to 50 years in prison for a series of Facebook posts deemed insulting to the monarchy.
And in March last year, a man was jailed for two years for selling satirical calendars featuring rubber ducks that a court said defamed the king.
The yellow bath toys were an unexpected symbol of mass youth-led street protests that shook Bangkok in 2020.
Reform of the lese-majeste law, known in Thailand as 112 after the relevant section of the criminal code, was a major theme of the demonstrations, which featured unprecedented public criticism of the royal family.
More than 250 people have faced royal insult charges in the wake of the protests, according to Thai Lawyers for Human Rights, a legal group that handles many cases.
They include senior protest leaders and at least one elected MP.
