Rhona Smith, the UN Special Rapporteur on the situation of human rights in Cambodia on Friday issued a statement expressing “grave concerns” over the “heightened political crackdown across Cambodia”.

She also called on the government to respect the rights to freedom of opinion, expression and assembly.

But government spokesperson Phay Siphan said on Friday that Smith should not interfere in Cambodia's sovereignty, and that the Kingdom had merely taken action to protect peace and prevent activities that could lead to toppling the elected government.

Smith said she had since August received information that at least 89 people had been charged with “plotting against the state”, and at least 52 people had been arrested in 20 provinces. That, she said, brought the number to more than 200.

“The rapid increase in the number of arrests and serious charges filed against CNRP members is alarming.

“Arrests based on exercising the rights to freedom of opinion and expression, through political discourse and commenting on public affairs, are not permitted. Cambodia must respect its international obligations,” she said.

Smith said civil society organisations had reported increased surveillance and monitoring by local authorities, as well as limitations put on their activities. She stressed that civil society organisations should be able to work freely in Cambodia.

On the deployment of security forces along the border to protect security ahead of Sam Rainsy’s announced date of return on Saturday, Smith urged law enforcement officials to apply non-violent means.

She said Cambodians had the right to “safely enjoy these peaceful cultural celebrations free from fear”.

“I call on the government and all parties to reduce escalations in tensions and seek dialogue in a peaceful environment that allows for diverging political voices to be expressed, and to avoid any further restrictions on fundamental freedoms that are necessary for the enjoyment of human rights by all,” she said.

In response, Siphan said: “The deployment of armed forces along border areas and troop movements are just some of the duties of the government in protecting peace, stability and obedience to the law which no one can interfere with.

“These are not repressive to the freedom of citizens but to protect them. We appeal to all people not to join the coup plot led by Sam Rainsy and his group,” Siphan said.

Rejecting Smith’s appeal for dialogue, Siphan said the government had no reason to seek dialogue with coup plotters as this activity was against the law.