By Prak Chan Thul
PHNOM PENH (Reuters) - Cambodia's Supreme Court on Friday upheld the conviction of an opposition MP jailed for 2-1/2 years for posting a map on Facebook professing to show the government had ceded territory to Vietnam.
Cambodia has for centuries fretted about its much bigger neighbors - Vietnam to the east and Thailand to the northwest - encroaching on its territory. The issue remains emotive and many Cambodians are suspicious of both countries.
In 2016, the Phnom Penh Municipal Court in the Cambodian capital had found Um Sam An, of the now dissolved opposition Cambodia National Rescue Party (CNRP), guilty of incitement to cause discrimination and instability when he repeatedly posted "fake" border maps on the social media site.
Sam An was also fined $1,000.
"The Supreme Court rejects the appeal complaint filed by lawyer Chuong Chou Ngy, who represents Um Sam An, and upholds the verdict by the Appeal Court as valid," Presiding Judge Soeng Panhavuth told the court on Friday.
The CNRP was dissolved last year at the request of Prime Minister Hun Sen's government after the arrest of party leader Kem Sokha, who was accused of plotting to take power with American help, charges he says were politically motivated.
The U.S. embassy has rejected government accusations as "inaccurate, misleading and baseless" and called for the release of detained opposition leader Kem Sokha.
The dissolution of the party has been condemned by Western aid donors who have said the general election in July cannot now be credible. Hun Sen, 65, is expected to win easily.
Um Sam An denied the charges against him, saying that as a member of parliament, he had immunity from prosecution.
"My detention has been illegal," Um Sam An told the court on Friday. "And as a member of parliament, I have the right to express opinions without being arrested, or fear of being arrested," he said.
(Reporting by Prak Chan Thul; Editing by Clarence Fernandez)