Somyot Prueksakasemsuk, editor of "Voice of the Oppressed", gestures as he walks near a prison cell at the criminal court in Bangkok.

Bangkok - A prominent Thai political activist accused of insulting the monarchy was jailed for 11 years on Wednesday in the latest tough sentence under the kingdom's controversial lese majeste law.

The Criminal Court in Bangkok convicted former magazine editor Somyot Prueksakasemsuk in connection with two articles deemed offensive to the royal family.

“We accept the ruling but we will appeal,” his lawyer Karom Polpornklang said after the verdict.

“I can confirm that he did not intend to violate article 112,” he said, referring to the lese majeste legislation. “He was doing his job as a journalist. We will seek bail for him.”

Rights campaigners denounced the conviction of Somyot, who was brought to court in shackles having been held for more than a year without bail.

“The courts seem to have adopted the role of chief protector of the monarchy at the expense of free expression rights,” said Brad Adams, Asia director at New York-based Human Rights Watch.

“The court's ruling appears to be more about Somyot's strong support for amending the lese majeste law than about any harm incurred by the monarchy.”

Somyot, who was arrested in April 2011, is a supporter of the “Red Shirt” protest group, which is broadly loyal to ousted former premier Thaksin Shinawatra.

The royal family is a highly sensitive subject in politically turbulent Thailand. King Bhumibol Adulyadej, 85, is revered by many Thais but has been in hospital since September 2009.

Rights campaigners say that the lese majeste law has been politicised, noting that many of those charged are linked to the Red Shirt movement.

Under the legislation, anyone convicted of insulting the Thai king, queen, heir or regent faces up to 15 years in prison on each count.

Thailand has been riven by political divisions since Thaksin was topped by royalist generals in a coup in 2006.

Two months of mass street protests by the Red Shirts against the previous government in early 2010 triggered the kingdom's worst civil violence in decades with 90 people killed, mostly in a bloody military crackdown.

Many Red Shirts seek the return of Thaksin, a former telecoms tycoon who lives overseas to avoid a prison sentence for corruption that he contends is politically motivated. - AFP