MOSCOW—A Russian court denied an appeal by Alexei Navalny, sealing an earlier ruling that would see the prominent Kremlin critic and anticorruption activist spend a lengthy sentence in a penal colony.
Mr. Navalny, whose detention in January sparked mass protests that mushroomed into a broader act of defiance against Russian President Vladimir Putin, was sentenced earlier this month for violating the conditions of a suspended sentence from 2014. Mr. Navalny was detained upon returning from Germany, where he spent months recovering from a poison attack that he blames on Mr. Putin. The Kremlin denies any involvement.
The rallies, which at one point saw over 40,000 people on the streets of Moscow and thousands more across the country, were met with a sweeping crackdown by the authorities, who detained more than 10,000. While Mr. Navalny’s allies have temporarily suspended large-scale protests until the spring, the protest wave has cemented his position as Mr. Putin’s most vocal critic and a potent threat to the Kremlin leader’s two-decade-old rule.
At the hearing on Saturday, Mr. Navalny appeared inside a glass cage for defendants and flashed a “V” sign for victory. He rejected the notion that he was hiding from justice, saying that his whereabouts were publicly known, and he described the legal process as absurd.
“If I was hiding, I wouldn’t be standing here in this aquarium,” Mr. Navalny told the court.