Prime Minister Hun Sen has lashed out at his royalist opponent Prince Norodom Ranariddh, warning that his recent return to politics could drag the monarchy back into politics.

Speaking at the inauguration of a new university building in Battambang province yesterday, Hun Sen warned Ranariddh – who announced his return to political life this week – against doing politics as a representative of the Royal Palace.

“You can do whatever you want, but there is one thing: If you do politics it will be linked to the monarchy, you have to be clear on this point,” he said in reference to Ranariddh, who is a senior adviser to King Norodom Sihamoni.

“If you want to do politics, you have to quit the Supreme Council as adviser to the King, otherwise the King will lose neutrality on the matter of politics. The name of the King will be used for propaganda, saying I am a brother of the King, I am the son of former King, and it will link the King with politics.”

Last weekend, Ranariddh said he would return to head the Norodom Ranariddh Party more than two years after he walked away from politics.

Speaking to supporters in Kampong Cham, he issued a stinging denunciation of his former colleagues in Funcinpec, the royalist party he led to victory in the 1993 elections, saying its current leadership had sold itself out to the ruling Cambodian People’s Party in exchange for minor government posts.

He also issued a call for Funcinpec members to defect to his camp.

Hun Sen yesterday reiterated earlier warnings that Funcinpec government officials attempting to defect to Ranariddh would be fired from their government posts.

“I would like to say clearly that with Funcinpec, whether they receive less or more [National Assembly] seats, we will still work together because we have worked together for years, and there is no need for others,” Hun Sen said. “Please don’t confuse and do anything disorderly to lie to others.”

Noranarith Anandayath, chief of Prince Ranariddh’s cabinet, declined to comment on Hun Sen’s comments, except to say that there were many other royal advisers involved with politics.

In yesterday’s speech, the premier also criticised opposition leader Sam Rainsy for filing an international complaint against him in connection with the so-called “K5 plan”.

Hun Sen said the plan – devised in 1984-85 as a response to the continuing threat from Khmer Rouge insurgents – would not have been implemented were it not for the United Nations and Western governments supporting resistance factions including the KR.

“At that time, if there was a trial, the UN should be on trial first as it recognised the Khmer Rouge and allowed the Khmer Rouge to sit in the UN,” he said.

Hun Sen did not mention Sam Rainsy by name, but in October, the self-exiled politician announced his plan to file an international complaint accusing Hun Sen of crimes against humanity in connection with the K5 plan.