Kremlin critic Vladimir Kara-Murza was jailed for 25 years by a Moscow court on Monday, the harshest sentence of its kind since Russia invaded Ukraine, after being convicted of treason and other offenses in a trial he said was politically-motivated.

Kara-Murza, 41, a father of three and an opposition politician who holds Russian and British passports, spoke out against President Vladimir Putin for years and successfully lobbied Western governments to impose sanctions on Russia and individual Russians for purported human rights violations.

State prosecutors, who had requested a 25-year term, had accused him of treason, among other offenses, and of discrediting the Russian military after spreading "knowingly false information" about its conduct in what Moscow calls its "special military operation" in Ukraine.