Ho Vann, a Sam Rainsy Party lawmaker who had his parliamentary immunity pulled earlier this month, is in the US to meet other opposition party officials.

Ho Vann arrived in Massachusetts last weekend, following a June 22 vote in the National Assembly to suspend his immunity for a pending case in Phnom Penh court.

He faces charges of defamation from a group of 22 military officials who were angered when he publicly questioned the quality of certificates they’d received from the Vietnamese government.

“I’ve come to the US at the invitation of our party branch and will meet our party activists, who need explanations from the party and from our country,” he told VOA Khmer by phone. “After that I will go to join a meeting, according to a previous plan, in Italy.”

Rights groups have questioned the immunity pull, claiming it threatens democracy and protections for lawmakers to speak freely.

A second SRP lawmaker, Mu Sochua, who is facing a defamation suit by Prime Minister Hun Sen, also had her immunity suspended in the National Assembly vote.

Hun Sen’s ruling Cambodian People’s Party controls a vast majority of National Assembly seats, and the vote raised questions about the separation of the legislative and executive branches of government.