UK sanctions Russian figures after British Jewish Putin critic jailed for 25 years

He also said Russia was run by "a regime of murderers" in an interview with CNN.

The Jewish dissident has also over the years pleaded in the United States and Europe for the adoption of individual sanctions against Russian officials.

Kara-Murza, whose mother is Jewish, was arrested two months after the war began, accused of spreading false information about the armed forces and declared a "foreign agent". 

During his trial, he compared the wording of the charges against him with that used by Soviet dictator Josef Stalin's secret police in the 1930s, when Kara-Murza's own grandfather was sent to a Gulag prison camp in Russia's far east.

The RIA state news agency reported on Monday that an appeal against his sentence had been rejected. 

UK Prime Minister Rishi Sunak labelled the rejection of the appeal by judges in Moscow as "desperate and unfounded", adding on Twitter: "He should be released immediately. The United Kingdom stands with him and his family."

The UK Government announced that it had sanctioned six individuals, including two Moscow city court judges, for their involvement in the conviction of Kara-Murza.

Foreign Secretary James Cleverly said: "The rejection of Vladimir Kara-Murza's appeal following his sentencing on bogus charges highlights the depravity of the Russian regime and their complete disregard for human rights and freedom of expression.

"Today we've sanctioned six people connected with his case, sending a clear message that the UK will not stand for this treatment of one of its citizens."