Cambodia's Supreme Court dissolved the country's main opposition party and banned more than 100 of its politicians from office for five years on Thursday, in a ruling blasted by a rights groups as the "death" of the nation's democracy.
The verdict was widely expected from a justice system heavily warped by the influence of long-standing premier Hun Sen, who is accused of ruthlessly targeting rivals in the run-up to 2018 polls.
But it nevertheless delivered a crushing blow to what remained of the embattled Cambodia National Rescue Party (CNRP), the only party with a fighting chance to break the authoritarian leader's 32-year grip on power.
Judge Dith Munty, himself a member of Hun Sen's ruling CPP party, said the court had also banned 118 CNRP politicians from office for five years, in what rights groups blasted as a mockery of judicial independence that turned Cambodia into a de facto one party state.
The judge said the CNRP, by boycotting the trial, had effectively confessed to the government-levied accusation of conspiring with the United States and other foreign actors to plot a revolution.
The CNRP and Washington have rejected those charges as bogus.
In a statement the CNRP said it "still considers itself to be a legitimate party with a mandate from half of the Cambodian population", describing the court case as "politically motivated and made under pressure to follow the wish of the ruling party that is trying to rid CNRP from the political field".
In a televised address Thursday evening, Hun Sen called for calm and said 2018 elections would be held as scheduled.
"The government supports the decision of the Supreme Court and its ruling will ensure peace," said the premier, who has staked his reputation on bringing stability and growth to Cambodia after decades of civil war.
Call for no foreign assistance for poll
Yet rights groups warned the verdict stripped stripped next year's election of any credibility and gravely imperiled the country's democratic aspirations.
"This is the death of democracy in Cambodia," said Phil Robertson from Human Rights Watch, calling on foreign partners to suspend any assistance for the 2018 poll.
The International Commission of Jurists said Cambodia had crossed a "red line," with CNRP's dissolution stripping millions of voters of a chance to freely choose their representatives.
The CNRP's parliament seats and local posts will now be redistributed to other parties after the government amended laws last month to allow the reallocation.
The verdict is the culmination of a methodical strangling of dissent in Cambodia that began after the CNRP nearly unseated Hun Sen in the last national election in 2013, rattling the premier.
The crackdown accelerated dramatically after the party faired well in local elections this July, despite weathering a series of legal attacks against its leadership.
Several months later CNRP president Kem Sokha was suddenly thrown into jail and charged with treason over the same accusations of plotting a revolution.
In a tweet responding to the ruling, his daughter Monovithya Kem called on Cambodia's western donors to stop backing next year's polls.
"Time for EU, Japan, Australia and the US to declare withdrawal from elections assistance, or they become accomplice to the death of Cambodia democracy," she wrote.
Kem Sokha's arrest, and the threat of a 30 year prison sentence, sent more than half of the party's 55 lawmakers fleeing into exile out of fear.
Hun Sen, a former Khmer Rouge commander who defected, has a long history of undercutting his rivals through well-timed crackdowns and dubious court cases.
But observers say the current climate of repression is harsher and longer-lasting than previous clampdowns, with Hun Sen foregoing even the pretense of respecting human rights and a free press.
In addition to assaults against the CNRP, his government has in recent months shut down a series of outspoken NGOs and independent news outlets -- including the respected Cambodia Daily.
Analysts say the premier has been emboldened by financial backing from Beijing, which has lavished the poor country with investment that has made it less dependent on aid from Western democracies.