“I grew up in the Labour Party. It makes me absolutely furious; I’m absolutely spitting tacks. Why don’t they just get their act together?”

As she prepared for the publication of her new book on antisemitism today, Rabbi Julia Neuberger recalled her “anger and frustration” that has been building for a number of years, in proportion with the rise of left-wing antisemitism.

The country’s second-ever female rabbi said: “Some people just don’t seem to get it. Jeremy Corbyn — why didn’t he speak out instantly against the Mear One [antisemitic mural]? It could have come straight out of Der Stürmer!”

But while the impetus to write the book — Antisemitism: What it is. What it isn’t. Why it matters (Weidenfeld & Nicolson) — may have been borne of anger, the target audience are “very well-disposed people, definitely not antisemites” who have approached her seeking clarification on the issue.

Rabbi Neuberger, a cross-bench peer and a trustee of several charities, backs the right for people to speak out against the actions of Israel.

But, according to one of her central theses, anti-Zionism “morphs into antisemitism… when their tone in their criticism of Israel is such that they would not use it about other countries”.

She added: “They need to look themselves in the eye and ask whether they’re actually being antisemitic, and not just critical of the state of Israel.

“This isn’t a book for Jews. This is a book for people who don’t understand it but are genuinely interested and puzzled.”

Inevitably, the book focuses on left-wing antisemitism. As for Jeremy Corbyn, Rabbi Neuberger stopped short of calling him an antisemite, but said he “has behaved like an antisemite”.

She attributed part of the problem to “Stalinist anti-capitalism”, and an inability to recognise that Jews, who may be seen as “to be doing too well”, as possible victims of racism.

But the book also delves into the history of antisemitism, from the ancient world to modern day, and right-wing racism, including contemporary Islamophobia “which can morph quite quickly” into antisemitism.

Antisemitism: What it is. What it isn’t. Why it matters is published on Thursday.