PHNOM PENH (Reuters) - Cambodia’s detained opposition leader Kem Sokha has declined to join a new movement, founded by prominent exiles following a ban on the main opposition party, his lawyer said on Saturday.

Cambodia's Prime Minister Hun Sen arrives to attend the Cambodian People's Party (CPP) congress in Phnom Penh, Cambodia January 19, 2018. REUTERS/Samrang Pring

The Cambodia National Rescue Movement (CNRM) was announced on Jan. 13 by Prime Minister Hun Sen’s veteran foe Sam Rainsy following the dissolution of the Cambodia National Rescue Party (CNRP) last year and the arrest of its leader, Kem Sokha.

Signs of division emerged among CNRP members over the CNRM, of which Sam Rainsy said could launch appeals to the people to organize peaceful protests, to workers to go on strike and to the armed forces to join them.

Kem Sokha’s lawyer Pheng Heng said on Saturday that the opposition leader had declined to join the CNRM, saying that he will continue to work under the CNRP.

“He said that he doesn’t join or support any movement and he’s still with the CNRP, of which more than three million people had voted for it in recent elections,” Pheng Heng told Reuters, quoting Kem Sokha when he visited him in prison on Friday.

Kem Sokha’s daughter Kem Monovithya said that it’s important not to get distracted from the CNRP.

“I continue to do what I have been doing under CNRP framework, in consultation with the imprisoned leader Kem Sokha, to advocate for free and fair elections in Cambodia,” Kem Monovithya said.

Sam Rainsy, who has lived in France since 2015 to avoid a series of convictions, didn’t respond to Reuters request for comment.

The CNRP was dissolved after the arrest of Kem Sokha, who was accused of plotting to take power with American help - charges he says were politically motivated because the threat the party posed to Hun Sen at this year’s election.

The dissolution of the party and arrest of Kem Sokha have been condemned by Western aid donors who have said the election cannot now be credible. Hun Sen, 65, is expected to win easily.

The CNRP was set up in 2012 to unify Sam Rainsy’s and Kem Sokha’s separate parties. Its success in a 2013 general election and local elections last year had shown what a powerful electoral force it had become.

(This version of the story corrects the date in the second paragraph from July 13 to Jan. 13.)