Michael Fabricant is MP for Lichfield.

As the diplomatic fallout from the attempted assassination of a former Russian agent in Salisbury rages on, a familiar pattern of deranged conspiracy is emerging. Beyond the predictable rush from certain political figures to exonerate Russia’s involvement, a number of assorted cranks from the political fringes have constructed a more sinister narrative.

They suggest that not only did Russia have nothing to do with the attacks, but that instead Israel is to blame.  A chief proponent of this theory is Craig Murray, who was the British ambassador to Uzbekistan between 2002 and 2004, before being moved under difficult circumstances.  Murray recently published an article on his website where he speculates, without evidence, that Israel could be behind the attack as a part of a plot to “damage Russia’s international position”.

Craig Murray’s far-fetched musings have in turn been picked up by the prominent left-wing blog The Canary, which has been shared widely on social media.  Meanwhile on the far-right, Nick Griffin, the former BNP leader, took to Twitter recently to hint that the UK was being manipulated into “prodding the Russian bear” by “Israel and Al-Qaeda”. Thankfully, this nonsense has not made its way into the mainstream, but it follows an established pattern of blaming Israel or “Zionists”, for any and all of the world’s ills.

Wherever there is tragedy, fingers are inevitably pointed at Israel. In the vast web of conspiracy theories that can be found on the internet, Israel is referenced with preposterous frequency for a country with a population of less than nine million. As the reaction to the Salisbury attack shows, people with an agenda will always find ways of shoehorning Israel into their deluded fantasies.

Why does this matter? The problem is that these are not simply harmless conspiracies. Often, they act as less than subtle dog whistles which prey on already existing prejudices that exist towards the Jewish community. It is worth remembering that many anti-Israel conspiracy theories are steeped in the language of old-fashioned anti-Semitism.  Proponents of these theories regularly portray Israel as the “puppet master” of global conflict. Such imagery is reminiscent of anti-Jewish cartoons from the early 20th century, which depicted hook-nosed men with sidelocks controlling the world for their own greedy ends.

In an attempt to muddy the waters, anti-Israel activists will often claim they are simply “anti-Zionist”, but such attempts at deflection should fool no-one. This is the stance taken by activist Jackie Walker for example, who was suspended from the Labour Party for making outrageous comments, such as accusing Jews of being the “chief financiers” of the slave trade. It is no coincidence that promoters of wild conspiracies involving Israel are usually the same people who decry the alleged influence of the “Israel lobby” in the US and the UK, harkening back to anti-Semitic tropes of Jewish world domination.

Unfortunately, peddlers of these untruths are having an effect. A 2015 YouGov survey for example found that one in six people in the UK believe that “Jews have too much power in the media”. With incidents of anti-semitism on the rise on both sides of the Atlantic, it is more important than ever that the conspiracies surrounding Israel are challenged. Failure to do so will simply reinforce dangerous stereotypes.

Prejudice against Israelis is all too often a gateway drug to prejudice against Jews in general, as was demonstrated by the spike of anti-semitic incidents recorded in Europe in the immediate aftermath of the 2014 Israel-Gaza conflict. It is of course important that legitimate criticism of Israeli policy is not automatically tarred with the brush of anti-Semitism. This is why it is vital that that sensible critics of Israel lead the charge against the conspiracy theorists.

Free speech must also be protected. It would be wrong to simply silence these kooks, as that would merely give credence to their delusions, and pour petrol on the bonfire of prejudice. Instead, the solution lies in aggressively challenging these conspiracies with facts, logic and a bit of condescension. Proponents of these theories need to realise just how ridiculous they sound when they put forward the idea that a small country like Israel is somehow secretly controlling the most powerful nations on Earth.