Anon Nampa was arrested in 2020 after making the call for change during mass anti-government protests.
A court in Thailand has jailed activist and lawyer Anon Nampa for four years after he made a taboo-breaking call for royal reform during protests three years ago.
On Tuesday, Bangkok’s Criminal Court also imposed a fine of 20,000 Thai baht ($551) on Anon for breaking an emergency decree that was in force at the time.
Anon’s lawyer said he would appeal against the ruling.
The charges stem from a protest in October 2020 when Anon also called for the resignation of then Prime Minister Prayuth Chan-ocha and a new constitution as he led thousands of mostly young people towards the government house where police eventually used force to break up the demonstration.
Anon previously told Al Jazeera that he knew the unprecedented call was likely to get him arrested in a country that maintains strict laws on royal insult known as lese-majeste.
The laws protect King Maha Vajiralongkorn and his close family from criticism.
The king made a rare walkabout in Bangkok in the month after the protests, calling Thailand the land of compromise.