Human rights groups are calling for the release of jailed Thai labour rights campaigner and magazine editor Somyot Prueksakasemsuk.

Bangkok’s Criminal Court convicted Prueksakasemsuk, a campaigner on behalf of garment workers, on two counts of Article 112 of Thailand’s Criminal Code, and jailed him for 11 years.

The case revolves around the publication of two magazine articles by Prueksakasemsuk in 2011 which were alleged to be insulting to the Thai monarch – forbidden under Article 112.

“Somyot is a prisoner of conscience,” said the Clean Clothes Campaign, in a joint statement with the Free Somyot Campaign and the Thai Labour Campaign.

“He was convicted solely for the exercise of his right to freedom of expression and opinion, and the right to participate in public life.”

The group added: “Today’s verdict is a serious blow to the rule of law in Thailand and will further contribute to self-censorship.”

Campaigners argue that the case has violated international human rights law, and particularly the International Covenant on Civil and Political Rights (ICCPR), which has been ratified by Thailand.

“If Thailand is to be in compliance with its binding international legal obligations to respect and protect basic rights, this unjust verdict against Somyot should be promptly overturned on appeal,” the groups said.