PRIME Minister Hun Sen said Wednesday that any opposition member who calls Cambodia an "autocracy" will be met with a lawsuit by the Cambodian People's Party.

Speaking at a graduation ceremony at the National Institute of Education in Phnom Penh, the prime minister told opposition members to exercise "caution" when describing the Kingdom.

"Be cautious about using [the] improper language of dictatorship, for sometimes there will be legal action," Hun Sen said.

"This regime rules according to the constitutional monarchy and the principle of liberal democracy and pluralism," he said.

Hun Sen did not name particular opposition members, but referenced opposition in the Sam Rainsy Party.

Yim Sovann, a lawmaker and spokesperson for the SRP, said that the prime minister's comments amounted to another threat against members of the SRP and its parliamentarians.

He said that housing evictions by armed forces of the ruling party and the suppression of peaceful demonstrations "has never happened in a democratic country".

"I am not accusing the prime minister, but he may very well realise himself: What is the country's rule? Is it democracy or autocracy?" Yim Sovann said.

"Look at Thailand, whose citizens have enough rights to express their opinion by holding peaceful demonstrations. Such a culture is not allowed in Cambodia."