On Tuesday morning, Mr. Hun Sen — who has maintained his grip on power for 33 years with a potent mix of military power, political guile and old-school thuggery — took to Facebook to deem the polls free and fair. The prime minister said there had been no pressure on voters to choose the Cambodian People’s Party.

“The absolute majority of people support democratic, liberal and multiparty elections, which is the biggest wish of the Cambodian people,” Mr. Hun Sen wrote on his Facebook page.

But Sunday’s electoral exercise can hardly be described as a display of multiparty democracy.

The 19 other parties that appeared on the ballot were tiny entities with little name recognition. Cambodians call them “firefly” parties, twinkling briefly during the electoral season to give a veneer of validity to the proceedings.

Rights groups, the United Nations and Western governments said the election had been compromised before a single ballot was cast. In November, the main opposition force, the Cambodia National Rescue Party, was ordered dissolved by the nation’s highest court. Its leader, Kem Sokha, is in jail, accused of plotting to overthrow the government with American support.

Independent local media outlets have been forced into silence. Western aid groups that had spent hundreds of millions of dollars over the years to nurture Cambodia’s fledgling democracy have been kicked out of the country.