By Prak Chan Thul and Amy Sawitta Lefevre
PHNOM PENH (Reuters) - Cambodia's Supreme Court dissolved the main opposition party on Thursday, leaving authoritarian Prime Minister Hun Sen clear to extend over three decades in power in a general election next year.
The government had asked the court to dissolve the Cambodia National Rescue Party (CNRP), which was accused of plotting to take power with help from the United States after the arrest of party leader Kem Sokha on Sept. 3.
The court ruling also ordered a five-year ban on political activity for 118 members of the opposition party, which had threatened a major challenge to Hun Sen, a former Khmer Rouge commander, at next year's election.
The party rejected the accusations as politically motivated. It did not send lawyers for the court ruling.
"It shows that Hun Sen will never stop if no one is stopping him," said Kem Monovithya, the daughter of Kem Sokha and also a party official. "The verdict is expected. It’s time for sanctions from the international community."
Western donors, who sponsored elections overseen by the United Nations in 1993 in the hope of founding an enduring democracy, had called for Kem Sokha's release.
But they have so far shown no appetite for sanctions against Cambodia's government, which is now closely allied to China. The United States and European Union missions in Cambodia declined immediate comment on the court ruling.
Dozens of police manned barriers outside the court in the center of Phnom Penh, a yellow-painted building ornamented with gold in traditional Cambodian style.
There was no sign of protests.
Few people on the streets wanted to talk about the ruling, the latest chapter in decades of maneuvering that have kept Hun Sen and his ruling Cambodian People's Party (CPP) in power across all levels in the country of 16 million.
"The Supreme Court's decision today is not to end democracy but to deter extremists in order to protect the people and the nation from destruction," said Huy Vannak, undersecretary of state at the interior ministry.
During Hun Sen's rule since 1985, Cambodia has been transformed from a failed state to a lower middle-income country with growth of around seven percent a year. Life expectancy has risen from 50 to 70.
Rights groups condemned the decision by the court, which is headed by a judge who is a member of the ruling party's permanent committee.
"The misuse of the courts to dissolve the CNRP is one of the gravest threats to human rights and representative democracy modern Cambodia has seen," said Kingsley Abbot of the Geneva-based International Commission of Jurists.
More than half the CNRP's members of parliament had already fled Cambodia, fearing detention in a crackdown on Hun Sen's critics, civil rights groups and independent media that began last year.
"We don’t know who is next," an editor at the Voice of Democracy radio station said. It was taken off air in August, but continued broadcasting through Facebook.
The CNRP's parliamentary seats will be redistributed to other government-aligned parties after its dissolution.
The party will also lose control of the councils that it won in local elections in June, when its strong showing in winning over 40 percent of them made clear the threat it posed to the ruling party next year.
(Writing by Amy Sawitta Lefevre; Editing by Clarence Fernandez, Robert Birsel)