He spent nine years in Soviet prisons after attempting to flee for Israel.
Now, Natan Sharansky, who went on to become Israel's deputy prime minister and a leading campaigner against anti-Semitism, is concerned about echoes of Soviet propaganda that he identifies in British political discourse.
In an interview with The Sunday Telegraph on a visit to London last week, Mr Sharansky, a so-called Refusenik who was praised by Maragaret Thatcher and Ronald Reagan for his human rights activism, says he fears that anti-Semitism has became a "mainstream" feature in the UK, having previously been confined to the extremes.
Specifically, he is concerned that Jeremy Corbyn and many of his supporters adopt a stance on Israel and Zionists that is reminiscent of the anti-Semitic rhetoric adopted by Stalin’s Soviet Union.
The 71-year-old, who was detained in the Soviet Union's Perm-35 labour camp, claims that Mr Corbyn's "extreme anti-Zionism" is "practically almost impossible to differ sometimes from anti-Semitism", citing his past links with members of Hamas and Labour's claim that the US and Israel are blocking peace in the region.
Following his time in the Israeli government, Mr Sharansky chaired the Jewish Agency, which helps Jews around the world to emigrate to Israel, for almost a decade.
He says that he hears "all the time from" from British Jews, including "some serious representatives of the Jewish community of London" who are preparing to move to Israel as a result of concerns about the impact of a government led by Mr Corbyn, with some families "buying apartments .... not for them, for their children."
Mr Sharansky ﬂew to London last week for the premiere of a ﬁlm, From Slavery to Freedom, a documentary which focuses on his life to chart the experiences of Refuseniks - Soviet Jews who were denied permission to emigrate.
His remarks come after James Cleverly, the Conservative chairman, told The Sunday Telegraph last week that Jewish friends of his had said that if Mr Corbyn "got anywhere near the levers of power, they would be out of here".
Last year a Survation poll for the Jewish Chronicle found that 40 per cent of British Jews would "seriously consider" leaving the country if Mr Corbyn became prime minister.
Mr Sharansky speaks of how he and fellow Refuseniks received particular support from Britons who "fought for us" during the Soviet era. "I was very grateful to Thatcher ... But, below her level, almost all of the activists were Labour", he says.
But he adds: "Corbyn, the leader of the Labour party who tomorrow can be prime minister, is not even trying to mask his extreme anti-Zionism, which is practically almost impossible to differ sometimes from anti-Semitism.
"But always, as we know from Russia, it starts from anti-Zionism and goes to classic anti-Semitism and then much further...
"It's surprising for me how Britain has become an example that anti-Semitism doesn't stand on the extremes. Its starts from the extremes and then goes to the mainstream."
Mr Sharansky, who served as Israel's deputy prime minister between 2001 and 2003, says statements and actions by the Labour leader and many of Mr Corbyn's followers fail a "three Ds" test he applies to questionable rhetoric about the country - namely whether it involves the demonisation, delegitimisation, or application of double standards.
"Israel, of course, has to be criticised as any other country, but if there is clear demonisation; clear delegitimisation - the right of Israel to exist as a Jewish democratic state is denied; or a clear double standard which is not used to any other country, that's classical .... of anti-Semitism, applied to collective Jews, the State of Israel."
Mr Sharansky says he ﬁnds anti-Semitism "easier to identify" because "I am from the Soviet Union, Stalin's Soviet Union. When the Soviet Union was speaking against Israel, everybody knew that it was about your Jewish neighbours ... and when Soviet propaganda was speaking about ‘cosmopolites’, everybody knew that it was about Jews. These rather cold words which were used for a very open anti-Semitic campaign against Jews who are 'not a loyal part of our population' and Israel was simply used as proof that they're not loyal."
In recent weeks The Sunday Telegraph disclosed that Mr Corbyn, a longstanding supporter of the Palestine Solidarity Campaign, had signed a statement in 2002 which accused Israel of carrying out a genocide of the Palestinian people and also appeared to back armed resistance to the Jewish state. Mr Corbyn has also been associated with a number of ﬁgures from Hamas, the militant Palestinian group, and in 2009 referred to representatives of the organisation as "friends" - a use of language he later said was simply intended to be "inclusive". In 2013 Mr Corbyn said that a group of Zionists had “no sense of irony” despite “having lived in this country for a very long time."
In September the Labour Party's annual conference adopted a motion stating that "recent actions by US and Israeli administrations are destroying prospects for peace in Palestine". A fringe event, attended by Diane Abbott, was addressed by Omar Barghouti, the co-founder of the Boycott, Divestment and Sanctions (BDS) campaign which calls for boycotts of Israeli goods and cultural events and the withdrawal of investments in the country.
In 2016 Mr Corbyn insisted: "I support the right of the State of Israel to exist, under the agreement of the original borders of 1948.” And, asked last year whether he held anti-Semitic views, he replied: "Absolutely not. I’ve spent my whole life opposing racism in any form."
Mr Sharansky, however, is unconvinced.
"If he doesn't have a problem with Jews, he has to [accept] that the Jews, as all the others, have the right to have their own state and that this state, should be criticised exactly like all the others," he says.
He suggests that Mr Corbyn and his supporters disproportionately target Israel compared to other regimes in Syria and South America.
"You insist that Israel will be judged by standards on which none of those countries is judged ... And you insist that Hamas is a legitimate organisation, more than that, you're proud to be their friend. So now you have to change your positions or stop lying that you have no problem with Jews," he says of Mr Corbyn.
"For me it is so easy because it looks exactly like Soviet rhetoric. There could be peace all over the world, but America and Israel, are two problems which don't permit people to live in peace. That was ofﬁcial Soviet propaganda, and the fact that it is now repeated by Iran and supported by Corbyn, that's very sad."