By Amy Sawitta Lefevre
BANGKOK (Reuters) - A Thai political activist who has started a hunger strike in protest against last month's coup filed charges on Tuesday against junta leader Prayuth Chan-ocha and members of the ruling military council for defaming the monarchy and acts of treason.
Chalad Vorachat, a retired navy lieutenant and serial hunger striker, argues in a complaint filed with a Bangkok criminal court that the army intervention based on Thailand's Martial Law Act had a shaky legal basis.
"In order to announce martial law, the country must be at war or there must be a violent conflict. Permission must also be granted by the prime minister and the monarch," Chalad told reporters outside the court.
"But soldiers pushed ahead with seizing power anyway."
Prayuth took power on May 22, saying the army needed to restore order after nearly seven months of political turmoil when protesters occupied areas of Bangkok to try to force out the government of Yingluck Shinawatra and wipe out the influence of her brother, former premier Thaksin Shinawatra.
At least 28 people were killed and more than 700 injured during the months of unrest.
The coup was the latest chapter in a power struggle stretching back almost a decade between the Bangkok-based establishment and supporters of Thaksin, whose stronghold is in the rural north and northeast.
The military rulers scrapped the constitution after the coup and Prayuth has said it will take a year or more before a general election can take place.
Chalad, 71, first went on hunger strike in 1992 against unelected Prime Minister General Suchinda Kraprayoon.
Chalad's action gave momentum to protests which the army eventually put down. Public outage over the violence forced former army commander Suchinda, who had seized power in a 1991 coup, to step down.
This time, based in front of Parliament House, Chalad has been on hunger strike for 19 days, demanding that the constitution be rewritten to make Thailand a truly democratic society.
He also wants to see an elected prime minister in office.
"If there is no prime minister from an election, then let me starve until my life is over," he said.
(Additional reporting by Panarat Thepgumpanat; Editing by Alan Raybould and Robert Birsel)