On Saturday, in the Danish city of Aarhus, a Europe-wide rally organised by the English Defence League will try to set up a European anti-Muslim movement. For Europe's far-right parties the rally, coming so soon after the murders in south-west France by a self-professed al-Qaida-following Muslim, marks a moment rich with potential political capital.

Yet it's also a delicate one, especially for Marine Le Pen. Well before the killings, Le Pen was assiduously courting Jews, even while her father and founder of the National Front, Jean-Marie Le Pen, was last month convicted of contesting crimes against humanity for saying that the Nazi occupation of France "wasn't particularly inhumane". Marine must disassociate herself from such sentiments without repudiating her father personally or alienating his supporters. To do so she's laced her oft-expressed Islamophobia (parts of France, she's said, are suffering a kind of Muslim "occupation") with a newfound "philozionism" (love of Zionism), which has extended even to hobnobbing with Israel's UN ambassador.

Almost all European far-right parties have come up with the same toxic cocktail. The Dutch MP Geert Wilders, leader of the anti-immigrant Freedom party, has compared the Qur'an to Mein Kampf. In Tel Aviv in 2010, he declared that "Islam threatens not only Israel, Islam threatens the whole world. If Jerusalem falls today, Athens and Rome, Amsterdam and Paris will fall tomorrow."

Meanwhile Filip Dewinter, leader of Belgium's Vlaams Belang party, which grew out of the Vlaams Blok Flemish nationalist party, many of whose members collaborated with the Nazis during the second world war, has proposed a quota on the number of young Belgian-born Muslims allowed in public swimming pools. Dewinter calls Judaism "a pillar of European society", yet associates with antisemites, while claiming that "multi-culture ... like Aids weakens the resistance of the European body", and "Islamophobia is a duty".

But the most rabidly Islamophobic European philozionist is Heinz-Christian Strache, head of the Austrian Freedom party, who compared foreigners to harmful insects and consorts with neo-Nazis. And yet where do we find Strache in December 2010? In Jerusalem alongside Dewinter, supporting Israel's right to defend itself.

In Scandinavia the anti-immigrant Danish People's party is a vocal supporter of Israel. And Siv Jensen, leader of the Norwegian Progress party and staunch supporter of Israel, has warned of the stealthy Islamicisation of Norway.

In Britain EDL leader Tommy Robinson, in his first public speech, sported a star of David. At anti-immigrant rallies, EDL banners read: "There is no place for Fascist Islamic Jew Haters in England".

So has the Jew, that fabled rootless cosmopolitan, now suddenly become the embodiment of European culture, the "us" against which the Muslim can be cast as "them"? It's not so simple. For a start, "traditional" antisemitism hasn't exactly evaporated. Look at Hungary, whose ultra-nationalist Jobbik party is unapologetically Holocaust-denying, or Lithuania, where revisionist MPs claim that the Jews were as responsible as the Nazis for the second world war.

What's more, the "philosemite", who professes to love Jews and attributes superior intelligence and culture to them, is often (though not always) another incarnation of the antisemite, who projects negative qualities on to them: both see "the Jew" as a unified racial category. Beneath the admiring surface, philozionism isn't really an appreciation of Jewish culture but rather the opportunistic endorsement of Israeli nationalism and power.

Indeed you can blithely sign up to both antisemitism and philozionism. Norwegian mass murderer Anders Behring Breivik described himself as "pro-Zionist" while claiming that Europe has a "considerable Jewish problem"; he saw himself as simultaneously anti-Nazi and pro-monoculturalism. The British National party's Nick Griffin once called the Holocaust the "Holohoax", subsequently supported Israel in its war "against the terrorists", but the day after the Oslo murders tweeted disparagingly that Breivik was a "Zionist".

Most Jews, apart from the Israeli right wing, aren't fooled. They see the whole iconography of Nazism – vermin and foreign bodies, infectious diseases and alien values – pressed into service once again, but this time directed at Muslims. They understand that "my enemy's enemy" can easily mutate into "with friends like these ...".

The philozionism of European nationalist parties has been scrutinised most closely by Adar Primor, the foreign editor of Haaretz newspaper, who insists that "they have not genuinely cast off their spiritual DNA, and ... aren't looking for anything except for Jewish absolution that will bring them closer to political power."

Similarly Dave Rich, spokesman of the Community Security Trust (CST), which monitors antisemitic incidents in Britain, told me that far-right philosemites "must think we're pretty stupid if they think we'll get taken in by that. The moment their perceived political gain disappears they revert to type. We completely reject their idea that they hate Muslims so they like Jews. What targets one community at one time can very easily move on to target another community if the climate changes." Rich's words, spoken before the murder of Jews in Toulouse, now sound chillingly prescient. The president of the French Jewish community, Richard Pasquier, judges Marine Le Pen more dangerous than her father.

French Muslim leaders rallied round Jewish communities last week. Next week sees the start of Passover, a festival celebrating the liberation of Jews from slavery in Egypt, when Jews often think about modern examples of oppression. Let's hope that French Jewish leaders use the occasion to rally round Muslim communities, and to remember that ultimately, racism is indiscriminate.

• This article was amended on 28 March 2012. It originally referred to the Community Security Trust as the Community Service Trust. This has now been corrected