BANGKOK • Thailand's Supreme Court yesterday jailed a firebrand opposition leader for a year for defaming a former prime minister, overturning two previous court rulings, in 2012 and 2014, that dismissed the charge against him.

Jatuporn Prompan is a key leader of the "red shirt" supporters of former prime minister Thaksin Shinawatra and his sister Yingluck, who also served as prime minister.

Jatuporn led street protests in 2010, when supporters of the populist former telecommunications tycoon Thaksin occupied a Bangkok shopping district for nearly two months, calling for then Prime Minister Abhisit Vejjajiva to resign.

The Supreme Court found Jatuporn guilty of calling Mr Abhisit a murderer in a speech during the protests, which ended in a bloody confrontation between the military and protesters in which more than 90 people were killed, most of them civilians.

Jatuporn's speech had not been fact-checked and had been made for political gain, causing damage to Mr Abhisit's reputation, the court said.

Confrontation between the Shinawatras and their legions of supporters, especially among the rural poor, on the one hand, and the military-dominated establishment, based in Bangkok, on the other, has divided Thailand for over a decade.

Jatuporn won a seat in Parliament in the 2011 general election, when Yingluck led the Shinawatras' party to victory.

Thaksin has lived in self-exile since 2008 to avoid a corruption conviction he says was politically motivated. Yingluck was ousted as prime minister days before a 2014 coup and she too faces trial in connection with accusations that she mismanaged an extravagant rice-subsidy programme.

The military government that has ruled since the 2014 coup has moved to suppress dissent and detained critics, many of them supporters of the Shinawatras.Jatuporn was already on bail for another defamation case brought by Mr Abhisit, and a terrorism charge in 2010.

REUTERS