A top Kremlin foe was convicted Monday on charges of treason and denigrating the Russian military and sentenced to 25 years in prison after a trial that marked the latest move in a relentless crackdown on the opposition amid the fighting in Ukraine.

Vladimir Kara-Murza, Jr., a prominent opposition activist who twice survived poisonings he blamed on the Kremlin, has been behind bars since his arrest a year ago. He has rejected the charges against him as political and likened the judicial proceedings against him to the show trials during the rule of Soviet dictator Josef Stalin.

In his final statement last week

Kara-Murza, 41, said that he remains proud of standing up to Russian President Vladimir Putin’s “dictatorship” and his decision to send troops into Ukraine.

“I know that the day will come when the darkness engulfing our country will clear,” Kara-Murza, a father of three, said at his closed trial last week in remarks that were posted on social networks and Russian opposition media.

“And then our society will open its eyes and shudder when it realizes what terrible crimes were committed in its name.”

Amnesty International denounced the sentence as “yet another chilling example of the systematic repression of civil society, which has broadened and accelerated” after the Kremlin sent troops into Ukraine.

“This verdict wrongly conflates human rights activism with high treason’ and is reminiscent of Stalin-era repression,” Amnesty’s Russia Director, Natalia Zviagina, said in a statement.

The group declared Kara-Murza a prisoner of conscience convicted solely for his political beliefs and demanded his immediate and unconditional release.

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Kremlin spokesman Dmitry Peskov refused to comment on the sentence.

The charges against Kara-Murza stem from his March 2022 speech to the Arizona House of Representatives in which he denounced Russia’s military action in Ukraine. While he was in custody, investigators added the treason charges linked to his public speeches abroad.

Russia adopted a law criminalising spreading “false information” about its military days after it sent troops into Ukraine on Feb. 24, 2022. Authorities have used the law to stifle criticism of what the Kremlin calls “a special military operation.”

Kara-Murza, a journalist, was an associate of Russian opposition leader Boris Nemtsov, who was killed near the Kremlin in 2015. Kara-Murza survived poisonings in 2015 and 2017 that he blamed on the Kremlin. Russian officials have denied responsibility.

Kara-Murza’s health has deteriorated in custody, leading to the development of polyneuropathy in both his feet, according to his lawyers.

Another prominent opposition figure, Ilya Yashin, was sentenced to 8½ years in prison late last year on charges of discrediting the military.