Vladimir Putin’s opponents hope that Ukraine’s Kursk offensive will undermine his authority and might eventually lead to a coup. But if this happens, one of Russia’s bravest dissidents has a warning: his successor could be even worse. Oleg Orlov was among the 16 people released from Russian jails this month in the most historic prisoner exchange with the US since the Cold War, alongside the American reporter Evan Gershkovich and the activist Vladimir Kara-Murza.

Orlov was serving a sentence of two-and-a-half years for denouncing Russia’s invasion of Ukraine before his surprise release . Speaking to i from Berlin, where he is recovering from his time in captivity, he describes the “cruel” conditions he endured – of 12 people sharing primitive cells with only 10 beds. Nobody wants to see the downfall of Putin’s “fascist” regime more than 71-year-old Orlov, who is chairman of the Nobel Peace Prize-winning human rights organisation Memorial .

He suffered years of intimidation before his jail time and has mourned several murdered colleagues. He has been following news of the Kursk incursion. With Ukraine’s forces apparently controlling 1,000 sq km of Russian territory and still advancing , Orlov thinks this “small crack” in Russia’s defences – and its pride – has the potential to widen.

If it isn’t stopped, this could “lead to problems for Putin’s regime”. It is “quite possible” that an army commander might try to oust the president if t.