Cambodian Prime Minister Hun Sen has lashed out at the United Nations human rights envoy to Cambodia, after the diplomat criticized the country's human rights record and the prime minister himself.

Yash Ghai, the U.N.'s human rights envoy, ended his latest fact finding trip to Cambodia on Tuesday. Before leaving, he criticized the government for lacking a commitment to promote human rights. He also said that power is concentrated around "one individual," which, he added, is "not a precondition under which human rights can flourish".

In a scathing reply on Wednesday, that one individual, Prime Minister Hun Sen, said the U.N. envoy should stop giving advice to Cambodia. He said Ghai would no longer be welcome in the country, and should be fired by the U.N. secretary-general.

When contacted by VOA Wednesday, the U.N. human rights office in Phnom Penh refused to comment on Mr. Hun Sen's remarks.

In recent months, several human rights advocates and opposition politicians have been jailed or threatened with jail for defaming Mr. Hun Sen, who has ruled Cambodia since the 1980's. Human rights groups have criticized what they called a government crackdown on dissent.

While the prime minister has recently released his critics under pressure from the international community, Ghai says people in Cambodia are still "scared."

Ou Virak, spokesman of the Cambodian Center for Human Rights, says Ghai made a fair assessment of the Cambodian situation.

"I think he is right to point out that the fact that the power in Cambodia is actually very concentrated," he commented.

Ghai called for international donors to put pressure on the Phnom Penh government to implement reforms. Cambodia, still recovering from two decades of conflict and the murderous Khmer Rouge rule of the late 1970's, relies heavily on foreign aid.