Cambodia opposition leader Kem Sokha was denied bail Wednesday after almost a year in jail on treason charges that critics say were trumped up by premier Hun Sen to gift himself a free run in last month's election.
Kem Sokha was detained as part of a crackdown last year on the opposition Cambodia National Rescue Party (CNRP).
The party was dissolved in November, leaving Hun Sen to extend his 33-year stay in office at July's polls where his party won every parliamentary seat in a vote without a credible opposition.
On Wednesday the Supreme Court in capital Phnom Penh rejected an appeal by Kem Sokha's lawyers to give him bail on grounds of ill health.
Prosecutor Ouk Kimsith argued that if released, Kem Sokha could provoke "unrest in the society... his release would affect the political stability".
The opposition leader, held in a remote prison near the Vietnamese border, was not present at the hearing.
But lawyer Chan Chen said the 65-year-old leader needed to travel abroad for medical treatment.
He suffers from hypertension and diabetes, which his lawyers say has been exacerbated by his protracted jail time.
"My client did not commit the crimes," Chan Chen said.
His trial is yet to start.
The CNRP, which posed the most legitimate threat to Hun Sen's ruling Cambodia People's Party (CPP), was dissolved two months after Kem Sokha's arrest.
Without a viable opposition taking part in the election, the CPP swept all 125 parliamentary seats, rendering the country a one-party state.
Kem Sokha's supporters had hoped he would be freed once the result was beyond dispute.
Human Rights Watch called for Kem Sokha's immediate release, labelling the charges "fabricated" and "preposterous".
"The government's treatment of Kem Sokha and other political prisoners will lend insight into Cambodia's future after July's sham election," HRW's Brad Adams said in a statement late Tuesday.