The former journalist denies the charges against him, which are linked to his anti-war comments.
Image source, AFPOpposition activist Vladimir Kara-Murza has been sentenced to 25 years in jail in Russia for charges linked to his criticism of the war in Ukraine.
He was found guilty of treason, spreading “false” information about the Russian army and being affiliated with an “undesirable organisation”.
The Russian-British former journalist and politician is the latest of several Putin opponents to have been arrested or forced to flee Russia.
He has denied all of the charges.
His 25-year sentence was the top number sought by prosecutors and is the longest sentence an opposition figure has received so far.
Last week, he said in a statement: “I subscribe to every word that I have said … Not only do I not repent any of this, I am proud of it.”
“I know that the day will come when the darkness engulfing our country will clear,” he added in remarks posted online. “Our society will open its eyes and shudder when it realises what crimes were committed in its name.”
The judge who announced the sentence said it would be served in a “strict regime correctional colony” and that Mr Kara-Murza would be fined 400,000 roubles ($4,900; £4,000).
Mr Kara-Murza played a key role in persuading Western governments to sanction Russian officials for human rights abuses and corruption.
He was arrested a year ago in Moscow, initially for disobeying a police officer. More serious charges were levelled at him once he was in custody.
His case was partly based on a speech he made to politicians in the US last year, where he said Russia was committing war crimes in Ukraine with cluster bombs in residential areas and “the bombing of maternity hospitals and schools”.
Those claims have been independently documented – but deemed false by Russian investigators who said the defence ministry did “not permit the use of banned means… of conducting war” and insisted Ukraine’s civilian population was not a target.
Another charge stemmed from an event for political prisoners at which Mr Kara-Murza referred to what investigators called Russia’s “supposedly repressive policies”.
Last week, a copy of a speech he made to the closed court was released, in which he said his trial reminded him of a Stalin-era show trial of the 1930s.
“I only blame myself for one thing,” Mr Kara-Murza said. “I failed to convince enough of my compatriots and politicians in democratic countries of the danger that the current Kremlin regime poses for Russia and for the world.”
He nearly died twice after being poisoned.
Mr Kara-Murza’s sentence has been widely condemned, with the British government summoning its Russian ambassador.
“Russia’s lack of commitment to protecting fundamental human rights, including freedom of expression, is alarming,” British Foreign Secretary James Cleverly said in a statement.
The campaign group Human Rights Watch has described the verdict as a “travesty of justice”.
“Russian authorities should immediately vacate the verdict and unconditionally free him,” it wrote on social media.