A Russian court announced on Monday the imprisonment of Russian dissident Vladimir Kara-Murza for 25 years, after convicting him on several charges, including "high treason", the longest punitive period in Russia's modern history.

Kara-Murza, who has been in pre-trial detention since April 2022, was one of the Kremlin's last critics who were not imprisoned or moved into exile.

After a closed-door trial, the court announced that it had convicted Kara-Murza of "high treason", spreading "false information" about the Russian military and illegal work on behalf of an "undesirable" organization.

As a result, he was sentenced to 25 years in prison in a prison complex with a harsh system in response to the demand of the public prosecutor, reports AFP.

Russian news agencies quoted his lawyer Maria Esmont as saying that Kara-Murza, 41, would appeal the verdict, denouncing "gross violations of procedures" during the trial.

Vladimir Kara-Murza has been in pre-trial detention since April 2022 (Reuters)

International condemnation

The verdict drew condemnation from many Western countries and international organizations, with the United Nations calling for his immediate release.

High Commissioner for Human Rights Volker Türk said Kara-Murza had been tried on charges "apparently related to the legitimate exercise of his right to freedom of opinion" and called on "the Russian authorities to release him without delay".

For his part, US State Department spokesman Vidant Patel said in a statement, "We renew our call for the release of Kara-Murza in addition to the release of 400 political prisoners in Russia," considering that the verdict is "politically motivated."

The European Union condemned the "grossly severe" punishment imposed on dissidents. The British government also denounced the "politically motivated verdict" and demanded his "immediate release", announcing the recall of the Russian ambassador.

The German government also condemned "in the strongest terms" the sentencing of the Russian dissident, with a foreign ministry spokeswoman saying "we condemn this verdict in the strongest possible terms," adding that the verdict showed "the shocking level of repression that has been achieved in Russia."