Russia has rebuked Foreign Minister Nanaia Mahuta after she said Aotearoa “stands in solidarity” with a top Kremlin critic who was sentenced to 25 years in prison for treason.

Vladimir Kara-Murza, a political activist and journalist who twice survived poisonings that he blamed on Russian authorities, has rejected the charges against him as punishment for standing up to President Vladimir Putin and likened the proceedings to the show trials under Soviet dictator Josef Stalin.

His sentencing comes as part of the Kremlin’s relentless crackdown on critics of the war in Ukraine.

The charges against Kara-Murza, a dual Russian-British citizen who has been behind bars since his arrest a year ago, stem from a March 2022 speech to the Arizona House of Representatives in which he denounced Russia’s invasion of Ukraine, along with other speeches abroad, the Associated Press reported.

Human rights organisations and Western governments denounced the verdict and demanded his release. Amnesty International declared the 41-year-old to be a prisoner of conscience.

Today Mahuta tweeted that “Aotearoa New Zealand stands in solidarity with opposition politician Vladimir Kara-Murza, who has been unjustly sentenced to 25 years for advocating an end to Russia’s war in Ukraine”.

She tagged Kara-Murza in the tweet and included the hashtag “#FreeKaraMurza”.

Russian Ambassador to New Zealand Georgii Zuev tweeted back at Mahuta, calling such statements “unacceptable”.

 “Such statements can be qualified as an attempt to exert pressure on the Russian justice system and interfere in Russia’s internal affairs,” Zuev said in a tweet from the Russian Embassy in New Zealand account.

“We consider them unacceptable.”

Mahuta’s comment joins similar condemnation from Western governments including the United States, Canada, Britain and Germany.

“Vladimir Kara-Murza bravely denounced Russia’s invasion of Ukraine for what it was – a blatant violation of international law and the UN Charter,” British Foreign Secretary James Cleverly said in a statement.

The Foreign Office said it summoned Russia’s ambassador to the UK, Andrey Kelin, over the conviction. The British government previously sanctioned the judge presiding at the trial for human rights violations in another case and said it would consider taking further action to hold people accountable in Kara-Murza’s case.

The US State Department hailed Kara-Murza along with jailed Russian opposition leader Alexei Navalny and “many others who serve their country and their fellow citizens at great personal cost by boldly standing up for human rights and fundamental freedoms”. It renewed its call for the release of Kara-Murza and more than 400 other political prisoners in Russia.

United Nations High Commissioner for Human Rights Volker Türk called the sentence “another blow to the rule of law and civic space in the Russian Federation”.

Days after the invasion, Russia adopted a law criminalising spreading “false information” about its military. Authorities have used the law to stifle criticism of what the Kremlin calls its “special military operation” in Ukraine.

The sweeping campaign of repression is unprecedented since the Soviet era, effectively criminalising independent reporting on the conflict and any public criticism of it.

Last month, a Russian court convicted a father over social media posts critical of the war and sentenced him to two years in prison. His 13-year-old daughter, who drew an antiwar sketch at school, was sent to an orphanage. Days later, Russia’s security service arrested Evan Gershkovich, an American reporter for the Wall Street Journal, on espionage charges.

In a statement at the end of his trial, Kara-Murza said he was jailed for “many years of struggle against Putin’s dictatorship”, his criticism of the war in Ukraine and his long efforts to champion Western sanctions against Russian officials involved in human rights abuses.

“I know that the day will come when the darkness engulfing our country will dissipate,” the father of three told the court in remarks that were posted on his Twitter account. “This day will come as inevitably as spring comes to replace even the frostiest winter.”

- with Associated Press