Kem Samathida, daughter of imprisoned opposition leader Kem Sokha, responded last night to former CNRP head Sam Rainsy's assertions about her father's support for a new "movement" to put pressure on the government, asking the public to honour the will of her father and not “defame” him.

“On behalf of the family of Kem Sokha, I would like to confirm all the decisions of my father have been made by his will. He has never decided to do anything against his will for his safety. If he wanted to betray himself for the sake of safety, he would not continue to struggle in a country which he knew wanted to arrest him,” she wrote, an apparent reference to remarks made by Rainsy that Sokha actually supports the new Cambodia National Rescue Movement but cannot say so publicly out of fear.

Rainsy announced the CNRM earlier this month, saying it would put pressure on the government to reverse measures taken against the now-dissolved Cambodia National Rescue Party - including the jailing of Sokha - by calling for demonstrations. While some former party officials have shown support for it, others have said it only imperils Sokha, who is awaiting trial on widely decried "treason" charges in a Tbong Khmum prison.

Through his lawyer, Sokha announced on Saturday that he did not support the CNRM, though Rainsy challenged the sincerity of his disavowal.

“I would like to ask for an end to the defamation of my father … My father has a firm determination and wisdom,” Samathida wrote.

Samathida went on to call for “unity” and “solidarity” within the party. The new "movement" is supported by CNRP vice-presidents Mu Sochua and Eng Chhay Eang, bother former members of the Sam Rainsy Party, but not by many who used to make up Sokha’s Human Rights Party. The two merged to create the CNRP in 2012.

“Solidarity does not mean that we need to think like each other, but it means that we do not do harass each other,” she added.

Ou Chanroth, a CNRP lawmaker from the HRP wing of the party, said he did not support the movement, but downplayed the severity of a purported “rift” dividing the party.

“I think that the party still exists because the party is recognised by over 3 million people … If we use anything else, I think that it is unclear,” he said, referring to support for the CNRP during the 2013 national elections.

“It is not a rift, it is just a dispute in solving the national problem,” Chanroth said.

In an email today, Rainsy said the creation of the CNRM would go forward, with or without the overt support of Sokha.

"In my capacity as co-founder of the CNRP I must protect this party and prevent it from dying slowly because its current leadership is paralysed with the other co-founder and president Kem Sokha being detained and held hostage by [Prime Minister] Hun Sen," he said. "We must absolutely launch the CNRM to give a new momentum to the CNRP and prepare for its final victory over dictatorship so as to rescue our nation."