Cambodian opposition leader sentenced to two years jail

A Cambodian court has convicted an opposition party leader of inciting social disorder and sentenced him to two years jail, the latest legal assault on opponents and critics of Prime Minister Hun Manet's government.

The Phnom Penh Municipal Court also gave Nation Power Party president Sun Chanthy a permanent ban on voting or running for office and fined him $US1000 ($A1,606).

He was convicted in absentia. He chose not to attend Thursday's court hearing because he has been held in pre-trial detention almost 600 kilometres away and the drive would cause him to be carsick, his lawyer, Choung Chou Ngy said.

"He said to travel nearly 600 kilometres while handcuffed, it would feel like torture," the lawyer said.

Sun Chanthy, 41, was arrested in May this year at Phnom Penh International Airport after returning from a trip to Japan where he held a meeting with several hundred Cambodian overseas workers.

Sun Chanthy spoke there critically about Hun Manet's government and urged that opposition political parties be allowed to operate more freely.

Under former Prime Minister Hun Sen, who held power for almost four decades, Cambodia was widely criticised for human rights abuses that included suppression of freedom of speech and association.

He was succeeded last year by his American-educated son, Hun Manet, but there have been few signs of political liberalisation.

Cambodia's government has long been accused of using the judicial system to persecute critics and political opponents.

The government insists it promotes the rule of law under an electoral democracy, but political parties seen as mounting strong challenges to the ruling Cambodian People's Party have been dissolved by the courts or had their leaders jailed or harassed.

Sun Chanthy had reportedly criticised the government's system of unfairness in issuing special cards to some poor families that allow them to receive social welfare handouts.

The Justice Ministry explained that he was charged for his remarks about the cards because he had "twisted information" to dishonestly suggest that they would only be distributed to those who join the ruling Cambodian People's Party.

Sun Chanthy had been a top leader of the former Cambodia National Rescue Party and was closely associated with its chief Sam Rainsy, the harshest critic and most popular opponent of the Cambodian People's Party for decades.

Sam Rainsy has been in exile since 2016 to avoid serving prison sentences on charges of defamation, treason and other offences, which his supporters consider politically motivated.

The Cambodia National Rescue Party had been expected to present a strong challenge to the ruling party in the 2018 general election.

But as part of a sweeping crackdown on the opposition before the polls, the high court dissolved the party, and the Cambodian People's Party subsequently won every seat in the National Assembly.

Sun Chanthy then joined the Candlelight Party, the successor to the Cambodia National Rescue Party, but it in turn was barred from competing in the 2023 general election on a technicality.

He later helped form the Nation Power Party in October last year.