The exiled Russian oligarch Mikhail Khodorkovsky has said he has decided not to employ personal security guards in London despite the rising unease among the Russian diaspora, because he recognises that if the Russian president wants him dead “no amount of security measures can prevent that”.

He believes that the targeting of Sergei Skripal was a clear case of security agency retribution towards a defector, and said it had little bearing on the safety or otherwise of political and economic exiles in the UK. He said he was convinced that the death of the former Aeroflot executive Nikolai Glushkov was unconnected to the poisoning in Salisbury.

“During the Soviet era there weren’t many defectors from the security services, then their numbers began to increase, and now they are starting to kill these defectors. This is seen as a very clear message: that you can’t escape from the special services,” he said.

Khodorkovsky, who was Russia’s richest man when he owned the country’s largest oil company, Yukos, spent 10 years in prison on fraud and embezzlement charges that most observers believed to be politically motivated. He was released in 2013 after Putin pardoned him in a gesture designed to improve Russia’s image before the 2014 Winter Olympics.

Facebook Twitter Pinterest Boris Nemtsov in 2011, four years before his death. Photograph: Alexander Zemlianichenko/AP

“I am a well-known opponent of Putin, and he has a very strong aversion to me – but with me it is a different story,” he said at a breakfast briefing at the London headquarters of the Open Russia foundation, the pro-democracy organisation he set up after being released from prison.

He was told “semi-officially” that he was on a previous Kremlin hit list that also included Boris Nemtsov, the opposition leader who was killed in 2015. “I was much more concerned when Nemtsov was killed, but there was a huge scandal about that and the list has been annulled,” he said.

He expressed concern that British politicians were failing to deal with the attack on Skripal as a criminal act by Putin’s corrupt inner circle, and instead treating it as an act sanctioned by the Russian government.

“The Russian government is not involved in this. The government is made up of officials, who do the usual official stuff, and the only thing you can accuse them of is that from time to time they take bribes,” he said. “But there is clear distinction between the government and Putin’s circle. All this is the work of Putin’s circle. Given that this is not about Russia or the Russian government but the criminal group inside Russia’s circle, the method of fighting it should be the methods used to fight criminal gangs.”

He said the UK government should recognise that it was dealing with “an organised criminal group”, and needed first to find out precisely who was involved in that group and take action against them. “There are plenty of tools available to fight dirty money and corrupt politicians. This all needs to be investigated. You shouldn’t strike out against 146 million people.”

Asked whether the Salisbury attack was deliberately timed to shape Russian public opinion before the presidential elections on Sunday, when Putin was re-elected with a 76.7% share of the vote, Khodorkovsky was uncertain, saying: “Don’t exaggerate the significance of this for the Russian electorate. No one in Russia has a clue who Skripal is, apart from a narrow circle of people involved in the special services. For everyone else it just looks like: Great Britain threatens Russia. That’s it.”

He has had to become more of an expert in the field of nerve agents after his deputy at Open Russia, Vladimir Kara-Murza, was twice suspected to have been poisoned by unknown substances. “We talked to Russian doctors, British, US, Israelis, they all said that there were a huge number of substances that can be discovered only in the first few hours,” he said, indicating that a decision to use the nerve agent novichok – which remains detectable for longer – against Skripal could either be interpreted as revealing a desire to send out a clear signal or as “stupidity”.