A dissident freed by Russia in the biggest prisoner swap since the Cold War has vowed to return to the country one day.

Vladimir Kara-Murza told the BBC he initially thought he was being “led out to be executed” when prison officers arrived to get him in Siberia last month.

It was only after being moved to Moscow that the dual British-Russian citizen realised he was one of 24 prisoners to be freed in the exchange – including a Kremlin hit man.

But in his first joint interview with his wife Evgenia in Europe since they reunited, he defiantly reveals on Sunday with Laura Kuenssberg that he plans to return to Russia.

“When our plane was taking off from Vnukovo airport in Moscow en route to Ankara on 1 August, the FSB [Russian Federal Security Service] officer who was my personal escort sitting next to me turned to me and said, ‘Look out the window, this is the last time you’re seeing your motherland’,” he told me.

“And I just laughed in his face, and I said, ‘Look, man, I am a historian, I don’t just think, I don’t just believe, I know that I’ll be back home in Russia, and it’s going to happen much sooner than you can imagine’.”

Mr Kara-Murza, one of the Kremlin’s most vocal critics, was held in solitary confinement in a high security jail after receiving a 25-year sentence in April 2023 on charges of high treason.

Recalling the days before the huge Russia-West prisoner swap, he said: “I was asleep and suddenly the doors to my prison cell burst open and a group of prison officers barged in.

“I was woken up, I saw that it was dark, I asked what time it was, they said 3am. And they told me to get up and get ready in ten minutes.

“And at that moment, I was absolutely certain that I was being led out to be executed.

“But instead of the nearby wood, they took me to the airport, handcuffed with a prison convoy, boarded me on a plane and flew me to Moscow.”

Wall Street Journal reporter Evan Gershkovich and former US Marine Paul Whelan were also released by Russia in the exchange.

In the West, Russian security service hitman Vadim Krasikov was freed by Germany along with others elsewhere accused of intelligence activities.

The US, Norway, Poland and Slovenia also participated in what was the biggest swap since the Cold War between the West and Russia ended more than 30 years ago.

On Friday, Mr Kara-Murza met prime minister Sir Keir Starmer and Foreign Secretary David Lammy – and he is now urging Western governments to give stronger backing to Ukraine.

He is pushing for the release of thousands of other political prisoners who are still being held in Putin’s jails.

In their interview, to be broadcast on BBC One on Sunday at 9am, he and his wife talk about their reunion, their family and the moment they tasted freedom.

Mrs Kara Murza talks of her “immense joy” at having her husband back and seeing him with their three children.

“Having survived two assassination attempts and now this prison sentence, including eleven months in solitary confinement in horrendous conditions, he’s yet again alive and relatively healthy with us,” she said.

Watch the full interview on Sunday with Laura Kuenssberg on BBC One and iPlayer at 9am.