The Justice Ministry has ordered the opposition Cambodia National Rescue Party to stop “misinterpreting the law” by arguing that party leader Kem Sokha’s arrest was illegal due to his parliamentary immunity and a lack of evidence, while the National Assembly justified the arrest, claiming he was caught red-handed committing “treason”.

Sokha stands accused of conspiring with foreign powers to topple the government with “evidence” mainly based on a speech he gave in 2013, in which he discusses receiving US advice on political strategies.

Through its public messaging, however, the CNRP was misinterpreting articles “to confuse the public opinion with the intention to hide the wrongdoings of Kem Sokha”, according to a Justice Ministry statement.

The ministry then asks the CNRP to “stop confusing” the public and “let this matter be solved by the court”.

Kem Monovithya, deputy CNRP public affairs officer and Sokha’s daughter, saw this statement as a “threat”.

“They’re capable of doing anything, evidently,” she said.

Former CNRP youth leader Hing Soksan, who the Cambodia Daily reported to have escaped an arrest on Sunday, released an open letter to party supporters yesterday, claiming Sokha’s arrest was illegal and part of a government strategy to divide the party. He then called on supporters to “unite together, keep going with patience”.

Yet the National Assembly yesterday morning decided that his arrest was in accordance with the law, and will convene on Monday morning in an extraordinary session to decide whether the court can proceed with the case.

According to Monovithya, the CNRP will boycott the Monday session.

After yesterday’s meeting, Cambodian People’s Party lawmaker Chheang Vun presented pictures to the press depicting revolutions in the former Yugoslavia and Serbia, comparing them to Phnom Penh’s 2014 Veng Sreng protests, which were started over a disappointing minimum wage, and were violently quashed when security forces opened fire, killing at least five. The protests, he insisted, had to have been linked because, for instance, both involved stone throwing.

In his purportedly incriminating video, Sokha mentioned the example of Serbia, but appeared to back away from the popular protests used to topple accused war criminal Slobodan Milosevic there. Still, Vun said, “The crime is red-handed, as he said that it will continue.”

“It means that it is happening now,” he said, before going on to allude to swirling conspiracies of a US-backed colour revolution involving NGOs and the media. “You see NGOs and radio are continuing their activities and broadcasting to defend him. The National Democratic Institute was just expelled from Cambodia, USAID is doing its activities in Cambodia . . . So some activities don’t need to have a physical picture [for proof].”

But legal expert Sok Sam Oeun said the alleged crime didn’t fall under the category of red-handed crimes. An arrest, he said, had to take place at the crime scene or shortly after if the suspect fled. “It’s not a flagrant crime.”

The National Assembly has been criticised in the past for ignoring the constitutional clause requiring a two-thirds majority to lift immunity.

Meanwhile, investigating judge Ky Rithy rejected a request of five CNRP lawmakers to visit Sokha on Monday, as the case was under investigation. “The . . . visit is allowed only for lawyers and relatives of the accused,” the letter reads. Sokha’s wife Te Chanmono was permitted a prison visit yesterday.

Sokha’s lawyers, too, were allowed to meet him for just the second time yesterday, after having been denied access on Wednesday.

Lawyer Pheng Heng said Sokha invoked his right to not answer questions without his lawyers present during questioning from the investigating judge, which began on Tuesday.

He reiterated that Sokha’s arrest and charges were illegal. “We will submit a paper [today] to the court to release him and drop all charges,” he said.

Additional reporting by Ananth Baliga