Defence lawyers for jailed opposition leader Kem Sokha walked out of the courtroom today after the Court of Appeals refused to allow the Cambodia National Rescue Party co-founder to attend a hearing meant to determine the legality of his arrest and detention.

Reached after the hearing, Touch Tharith, Appeal Court spokesperson, said the presiding judge had upheld the legality of Sokha's detention, despite the lack of participation from either Sokha or his representation.

"This morning the judge of the Appeal Court decided that the decision of the investigating judge to put the accused Kem Sokha in pre-trial detention is correct," he said.

According to one of the defenders, Sam Sokong, the eight lawyers first requested the court to delay the hearing. “But the Appeal Court decided to continue the hearing, so the lawyer group decided to walk out of the courtroom, and then the Appeal Court continued the hearing,” he said.

Lawyer Choung Choungy said the judge argued that the hearing was related to procedural issues and not to the charges as such, so the presence of the accused wasn’t needed.

Sokha was arrested earlier this month and charged with “treason” based on a 2013 video in which he talks about having received advice from the US on political strategy. His lawyers challenged the legality of his arrest, claiming that he enjoys constitutionally mandated parliamentary immunity and arguing that it was illegal to arrest him after midnight for anything other than an in flagrante delicto – or “red-handed” – offence.

Authorities, however, have rejected this reasoning, claiming the purported crime was indeed a flagrant offence, allowing officers to arrest him at any time, and in spite of his immunity.

The government has frequently been accused of violating the constitutional immunity of lawmakers, and despite lacking the two-thirds majority required to approve the prosecution of a lawmaker, ruling Cambodian People’s Party parliamentarians have voted to allow Sokha’s case to proceed.

Lawyer Sokong said the judge’s decision violated the rights of the accused. “The accused’s rights are ensured by international rights and the Cambodian Constitution,” he said. “The accused has the right to provide evidence and answer questions [in person]. If the accused is not in the courtroom, it means the hearing is meaningless.”

He added that a group of lawyers were now on their way to Tbong Khmum province’s Correctional Centre 3, where the opposition leader is being held, to discuss further action.

Sokong also pointed out the irony of not allowing Sokha to attend today’s hearing.

"The court decided to detain the accused in order to [make him] appear in court, so why did they not bring him to the court now?" he asked.

Fellow defence lawyer Chan Chen said their client had to be present because “we, the lawyers, are not parties to the conflict”.

“His Excellency Kem Sokha is the only person to answer questions,” he said. “If he is not here, we the lawyers cannot attend.”

CNRP deputy chief Mu Sochua, who had gathered outside the court with other opposition lawmakers, called the process a “mock trial”.

“Mr Kem Sokha’s rights were being totally violated, so it comes to what we’ve been saying all along,” she said. “This is a political case with the goal to give the ruling party the upper hand with regards to the next elections. It’s not level playing field.”