A leading figure in European Jewry has warned that there is a “very possible reality” of Islamic State becoming a major force in the continent.

But European Jewish Congress President Moshe Kantor said that despite the danger, Jews should not consider packing their bags and leaving for Israel.

Dr Kantor told the JC in an interview in London that the jihadist terrorist group, which controls large swathes of Iraq and Syria, “can take over Europe. It’s a very possible reality”.

He accused European governments of allowing Islamic extremism and far-right groups to flourish, saying that “Europe has to deal with IS as its own problem”.

He warned that if a far-right group scored an electoral victory in one major country, it would have an impact across the continent.

“There is a strong probability in France and other countries of the far-right coming into power, and if it happens in a country like France, there will be a domino effect.”

The three-term EJC president, who has been in charge of the body representing the interests of Europe’s 2.5 million Jews since 2007, said levels of antisemitism were worse than at any time since the Second World War, and that rising hate suggested another major conflict could be on the way.

“Every time before a catastrophe, Jews have been attacked in Europe. It was the case before the First World War and the Second World War that there was a dramatic change in antisemitism, and now we see a dramatic change again.

“I am not saying, as many of my colleagues have pronounced, that World War Three has already started. But I am saying that there are a lot of symptoms — the level of hated in society, for example — which is symptomatic of the period just before a very severe crisis.

“The whole of Europe is guilty. There is too much tolerance of intolerance. Europe is not recognising the symptoms before catastrophe.”

Despite this gloomy prognosis, he rejected former Israeli deputy prime minister Natan Sharansky’s comments earlier this year that “we are seeing the beginning of the end of Jewish history in Europe”.

In an article in the JC Mr Sharansky wrote that antisemitism “is now so deep in the core of European political and intellectual leaders that practically every Jew is being asked to choose between being loyal to Israel and loyal to Europe.”

Dr Kantor said: “Natan Sharansky is a very good friend and a well-respected gentleman, but in this I disagree with him. European Jews have three options: accept the level of antisemitism, assimilate, or emigrate. There are safer places in the world, like America, Israel, Australia and Canada. I don’t think it will be safer there forever though.

“Is European Jewry disappearing? I don’t think so. It will be a decline of the public presence of Jews, but in our global history we have had much more severe situations, and we survived. It’s our tradition to survive.”

The 61-year-old knows all about resisting institutionalised discrimination. Growing up in Soviet Moscow, he had “practically zero traditional Jewish education,” but was still identified by his religion.

“The first time I heard it, I was seven years old, when a teacher told me: ‘Kantor, you are like a pig with a yarmulke’. I was young, I didn’t understand what she had in mind, but I understood that it was something bad.”

This early experience of prejudice shaped his views. “Every Jew in the world is, at one time at least, a victim of antisemitism. I’ve never seen a Jew who wasn’t.”