Cambodia’s exiled opposition leader Sam Rainsy has committed treason by inciting soldiers to defy orders, Prime Minister Hun Sen said on Wednesday, and he will face new legal action over the comments.

The threat of more legal action against Sam Rainsy, who has lived in France since 2015 to avoid a series of convictions, comes weeks after a court dissolved his opposition party, removing any significant challenge to Hun Sen extending his decades-long rule in a general election next year.

The dissolution of the Cambodia National Rescue Party (CNRP) has been condemned by the opposition, rights groups and some Western countries as the most serious blow to democracy since an international peace deal and UN-run elections in the early 1990s ended decades of war and genocide.

The United States has withdrawn an offer to help fund the election and the European Union has raised the possibility of withdrawing trade preferences.

Sam Rainsy, who stepped down as leader of the CNRP this year in what turned out to be a futile bid to forestall a ban on his party suggested in a video posted on his Facebook page on Tuesday that soldiers would not obey orders to shoot civilians. "Around the world, at any time, armed forces don’t obey orders given by dictators to kill people and we say that Hun Sen is not immortal, we must not protect Hun Sen," Sam Rainsy told supporters in Paris.

Hun Sen, who has held power for more than 32 years, said the military would file a lawsuit in response.

"This is a treasonous crime, an incitement of soldiers to disobey orders," Hun Sen told garment workers in Phnom Penh.

The Supreme Court banned the CNRP after its leader, Kem Sokha, who took over after Sam Rainsy stepped down, was arrested for allegedly plotting to overthrow the government with US help. Kem Sokha, who rejected the accusation, is in prison.

In an interview with Reuters last month, Sam Rainsy said Cambodia was at a "tipping point" and that Hun Sen would be driven from power like Zimbabwe’s Robert Mugabe.

He urged Western states to impose targeted sanctions.

A government crackdown on dissent has included the prosecution of several rights activists, reporters and the closure of several media outlets.

Sam Rainsy served as finance minister in an ill-fated coalition set up when Hun Sen refused to give up power after losing a UN-organised election in 1993. Hun Sen purged his coalition partners in a 1997 putsch.

Hun Sen has built close ties with China.

Chinese President Xi Jinping met with Hun Sen during the Communist Party of China (CPC) in Dialogue with World Political Parties High-Level Meeting on December 1.

Xi called Hun Sen a good friend, old friend and true friend of the CPC and the Chinese people.