To his immense credit, Vladimir Kara-Murza, the 43-year-old Russian opposition politician who was freed into exile as part of the West-Russia prisoner exchange last month, is less starry-eyed than many. He is engaging, highly astute and a historian, well-versed in the vagaries of Russia’s recent and more distant past. He has strong opinions, which he voices in a reasonable, modulated way. And he has a dream – a dream of a Russia that is democratic, free and welcomed back into its rightful place in Europe.

It should also be said that he has nothing but contempt for Putin. He blames the president for Russia having taken a catastrophically wrong course for the past 25 years and wants him to be held to account by a criminal court.

Kara-Murza was speaking in London on Friday on the latest leg of a European tour, following visits to France, Germany and Finland, where he was welcomed at the highest level. His stay in London was no different; he arrived at his press conference hot-foot from a meeting with Sir Keir Starmer.

Kara-Murza is unusual in the Russian opposition diaspora, and not just in his impeccable command of English and the elegance of his arguments. Having divided his time between Russia and the West for many years, he took the decision to return to Russia after its invasion of Ukraine in order to lead opposition to the war, in the belief that this could be done effectively only from inside Russia.

He shares this understanding of effective opposition from inside Russia with the late Alexei Navalny. He also returned voluntarily to his homeland from Germany, where he had been recuperating from an apparent assassination attempt while campaigning in Siberia. Both Navalny and Kara-Murza returned fully aware that they were likely to be arrested and could die in prison.

For Navalny, who died in an Arctic prison camp in February – officially of natural causes, though many, including Kara-Murza, believe he was murdered – that turned out indeed to be his fate. Kara-Murza’s destiny, however, was different. Sentenced to 25 years for treason, and held in a Siberian prison camp where he suffered increasingly poor health, he was among 16 Russians released into foreign exile in August. And while not an ungrateful beneficiary of the prisoner swap – he believes it saved his life – he laments that he must now work from abroad.

The problems of challenging Putin from abroad are always recognised by opposition figures and their Western supporters. Not being inside Russia, sharing the experience of their fellow countrymen and women, following the subtle and less subtle changes that happen from day to day, means that aspiring politicians in exile can soon lose touch with their homeland in ways that leave them less well-equipped to assume power, even in the event there is a vacuum to move into. Not only do they risk losing touch, but they can also be resented on their return by those who, for whatever reason, did not leave.

Kara-Murza is well aware of those dangers, but also observes that change can happen quite precipitately. Look, he points out, how both imperial Russia and the Soviet Union collapsed within days. He also notes how relatively common it is for a struggling nation or system to be brought down by a failed war, from the First World War, which was soon followed by the Russian Revolution, to, more recently the Soviet war in Afghanistan, which Kara-Murza sees as a factor in the demise of the USSR. He says that Ukraine must win this war and Russia must lose, and that Putin’s fall is inevitable.

In the time this will take – which he concedes is unknowable – he wants to set out a road map for a Russian transition, so that both Russia and the outside world can be ready, in a way that it wasn’t when the Soviet Union collapsed. That lack of preparedness, he says, led to missed chances to bring about the free, democratic Russia he wants to see integrated into Europe.

While wishful thinking is a common failing of diaspora oppositions, Kara-Murza seems more sanguine than most about the time change may take. His motto is: be prepared. A bigger obstacle in current circumstances than the survival powers of Putin, however, is the degree to which the opposition in exile is divided. It looks set to become ever more so, too.

There are already several centres of that aspiring opposition, with the London-based former energy magnate, Mikhail Khodorkovsky, one influential pole. There were suggestions that Navalny’s widow, Yulia, could become a unifier, when she pledged to continue her husband’s cause. But that has not happened.

Indeed, an attack on Navalny’s one-time right-hand man, Leonid Volkov, which took place in Lithuania in April, was attributed just in the past week not to the Kremlin, but to an individual with links to another opposition figure and former associate of Khodorkovsky. The individual in question, it should be said, denies all involvement.

Paving the way for a post-Putin democratic Russia may well be a cause all opposition figures can agree on. But how to do it, who should lead it, and what shape such an opposition should take remain ill-defined and contested. This is the complicated landscape of exiled opposition that Vladimir Kara-Murza has been parachuted into. He has a claim to be the opposition’s most articulate and best-qualified advocate, but it could be hard for him to find his place.

Mary Dejevsky is a writer and broadcaster. She was Moscow correspondent for The Times between 1988 and 1992. She has also been a correspondent from Paris, Washington and China.