The Ministry of Interior has said it will not allow any demonstrations in front of the Supreme Court during a hearing on Thursday to decide if the opposition CNRP will be dissolved, while the Koh Kong provincial governor’s office warned it will prevent residents from travelling to Phnom Penh to protest.

“The rally is totally banned at that area [the Supreme Court], and if there is resistance, we will implement the law at the scene and arrest them,” ministry spokesman Khieu Sopheak said.

“We just maintain security,” he said, adding there must not be any “disturbing noise” while the Supreme Court is deliberating.

The future of the Cambodia National Rescue Party – the only party that has proven capable of competing with the ruling Cambodian People’s Party in recent elections – is in jeopardy, and may be decided at Thursday’s hearing, following a complaint against it from the Ministry of Interior accusing it of conspiring against the state.

Despite what is widely seen as a coordinated offensive against the CNRP – with party head Kem Sokha detained on “treason” charges and much of its leadership having fled the country – the opposition party has not called for demonstrations.

Deputy CNRP President Pol Hamm said yesterday it would not do so for the hearing and had no plans for demonstrations in the works. The Interior Ministry’s Sopheak said despite issuing a preemptive ban, he didn’t expect any demonstrations, because of the opposition leadership’s fear of further arrests.

However, Kirth Chantharith, National Police spokesman, said that peaceful protests would be allowed in accordance with the law. “We have a law to do protests, peaceful protests,” he said. “When the situation is calm, the National Police are also calm . . . If the situation needs it, we will respond to it.”

Meanwhile, the Koh Kong provincial governor’s office issued an announcement on Saturday urging CNRP supporters to abandon the party and promising legal measures against protesters. “The provincial administration would like to tell the people and the activists for the CNRP to please stop supporting the party . . . If the authority finds out that activists . . . plan to protest the decision at the Supreme Court, the provincial authority will take action,” the letter reads.

Sok Sothy, the Koh Kong provincial spokesman, said authorities would physically prevent anybody who planned to protest from going to Phnom Penh.

The Constitution guarantees the “rights to strike and to organise peaceful demonstrations”. Under the law, authorities must be notified of any assembly but permission is to be considered granted except in rare circumstances, though authorities routinely block protests and other gatherings.

CNRP Deputy President Mu Sochua, meanwhile, said the state was “in total violation of the law” by preventing assembly. “Will they arrest everyone going to the city?” she asked.

Phil Robertson, of Human Rights Watch’s Asia division, said efforts to clamp down on dissent were another example of Prime Minister Hun Sen “rocketing to the top of rights violating leaders in ASEAN”.

“Threatening to crack down on peaceful protesters simply demanding their right to be heard shows that intimidation, fear, and violence is all the ruling CPP have left when it comes to engaging with the Cambodian people,” he said via email.