A British-Russian dissident released from a Siberian camp in a prisoner exchange has called for more such deals, describing them as “life-saving operations”.

Vladimir Kara-Murza was freed along with 15 others including western journalists and other Russian dissidents on August 1 in the most extensive prisoner swap with Russia since the Cold War.

He had by then spent more than two years in detention for his opposition to Russian president Vladimir Putin and the war in Ukraine, having been arrested in April 2022 and jailed for 25 years in 2023.

Speaking at a press conference in Westminster on Friday, Mr Kara-Murza urged western governments to pursue more prisoner exchanges, saying he woke every morning and went to bed every night thinking about dissidents left behind in Russian jails.

He said: “We must not stop, we must not rest, we must not relent until we get the others out.”

Asked whether he was concerned this could encourage Mr Putin to take more hostages, Mr Kara-Murza said he would continue to take prisoners in any case “because he is afraid of the truth”.

Arguing that the prisoner swap on August 1 had saved “16 human souls” from the “hell” of Russia’s prisons, he added: “It wasn’t a prisoner exchange, it was a life-saving operation and we need to look at it this way.”

Mr Kara-Murza’s press conference followed a breakfast meeting with Prime Minister Sir Keir Starmer and Foreign Secretary David Lammy in Downing Street in which he delivered his plea for more prisoner exchanges and stressed that Mr Putin must not be allowed to win in Ukraine or secure a “face-saving exit” from that conflict.

He also thanked Mr Lammy for advocating his cause as shadow foreign secretary, and told the press conference he would be meeting former foreign secretary Lord David Cameron to thank him for his efforts as well.

Some of Mr Kara-Murza’s supporters, including his wife Evgenia, had previously called for the Foreign Office to do more to secure his release, especially as he holds a British passport.

But on Friday, Mr Kara-Murza said Foreign Office officials along with politicians and others in the UK had ensured he never felt forgotten while he was imprisoned – something he said was the greatest fear of any political prisoner.

He said: “I am deeply grateful for that. I don’t know what was or was not happening behind the scenes, but to me the most important work is actually not behind the scenes, it’s out in public.

“Because unless people talk about prisoners, unless people say their names, unless people show their faces, no exchanges and no negotiations will ever happen.”

Looking to the future, Mr Kara-Murza said the Russian government would not endure, but its collapse would be swift and western governments must be ready to seize the opportunity to help create a free and democratic Russia.

He said: “I firmly and fundamentally believe that if we ever want to see a Europe that is whole, free and at peace with itself, that is only going to be possible with a democratic Russia.”

He concluded the press conference by wishing Mr Putin a long life, so he could be put on trial for his actions in both Russia and Ukraine.