A spokesman for Funcinpec said yesterday that the party had filed its complaint to dissolve the opposition CNRP because “they took all my supporters”, insisting that the waning royalist faction was the true defender of democracy in the Kingdom.

On Thursday, Funcinpec filed a complaint with the Ministry of Interior to dissolve the Cambodia National Rescue Party – the Kingdom’s largest opposition group – over a purported plot to topple the government. The ministry lodged its own complaint with the Supreme Court seeking the party’s dissolution the following day.

“You know why we did this,” Nheb Bun Chin, Funcinpec spokesman, said in an interview yesterday. “They took all my supporters. They took my customers. I used to have a big map, very famous.”

Funcinpec leader Prince Norodom Ranariddh actually won the Kingdom’s first democratic elections, but was forced into a power-sharing agreement with Hun Sen’s Cambodian People’s Party.

Before his mandate was out, Ranariddh was ousted by Hun Sen in bloody factional fighting, but was later allowed to return as the minority partner in a coalition with the ruling CPP. Since then, Funcinpec has slid ever further into irrelevance, failing to win a single National Assembly seat in the 2013 election, or a single commune chief seat in local elections this year.

Unprompted, Bun Chin yesterday denied any association with the ruling party, claiming that Funcinpec was “protecting its product” by attacking the CNRP. “Who gave birth to democracy in Cambodia? Not Mu Sochua, not [Sisowath] Thomico. Ranariddh,” he added, referring to prominent CNRP officials.

Bun Chin also questioned what the opposition has accomplished with its 55 National Assembly seats.

The National Election Committee recently claimed the CNRP’s seats would be redistributed to minor parties in the event of its dissolution, with the bulk going to Funcinpec, a move that appears to be at odds with Cambodia’s election law.

“We don’t even think about that,” Bun Chin said.

Dr Paul Chambers, a lecturer at Thailand’s Naresuan University, said historically, Funcinpec can only make “a vague claim” to being a champion of democracy, adding that its recent cooperation with the CPP “diminishes” any claims it once had. “Funcinpec could become either a parliamentary opposition party much milder than CNRP or in the worst case a satellite party clandestinely endorsed by CPP,” he said in an email.

CNRP whip and acting spokesman Son Chhay said only that he would “let the people judge” which party better represented human rights and democracy.

Chhay said the party has not yet consulted with lawyers or decided how to proceed following the Interior Ministry’s move to dissolve it. “We are only concerned with our duty at the moment,” he said, explaining lawmakers met yesterday about the upcoming National Assembly session starting Thursday.

“The case is not going to be a normal case . . . We don’t believe we have done anything wrong.”

The CNRP’s latest troubles began when party President Kem Sokha was arrested last month on charges of “treason”. The accusation stemmed from a 2013 video in which he described receiving advice from the US, and his arrest has drawn near-universal condemnation both at home and abroad.

Justice Ministry spokesman Chin Malin yesterday confirmed the Ministry of Interior – the body that filed the complaint against the CNRP – would also investigate it.

Analyst Lao Mong Hay said allowing the Interior Ministry to investigate its own complaint was a conflict of interest. “The court should conduct its own investigation,” he said. “When the court uses the Ministry of Interior, the accuser acts as the investigator. This is not right.”