There have been very few British comedies about Jewishness — and even fewer that actually made anyone laugh. But The Infidel, a comedy written by David Baddiel on a Jewish (and Muslim) theme, does just that, by poking fun at both religions.

The mother of Muslim minicab driver Mahmud dies suddenly. As he goes through her papers, he realises that he has been adopted as a baby… from a Jewish family.

Mahmud, played with tremendous zeal by Omid Djalili, becomes the original self-hating Jew. But however much he is appalled by the discovery he also wants to find out more about his identity and his family — a quest that leads him into an unlikely friendship with Jewish black-cab driver, Lenny (Richard Schiff).

Meanwhile, Mahmud’s travails multiply as his son, Rashid, prepares to become engaged to Uzma, whose stepfather, Arshad, is a hardline Muslim cleric.

There is some rich material for Baddiel and director Josh Appignanesi to get their teeth into and they do not disappoint. And Djalili, who served his Jewish apprenticeship by playing Fagin in the West End musical Oliver!, is convincing and charismatic as the semi-lapsed Muslim coming to terms with his new identity as he practices shrugging in the mirror, makes a speech with a Yiddish punchline at a barmitzvah, and pleads to be allowed to see his Jewish birth father, Izzy, who lies dying at the Jewish old people’s home.

The script pulls no punches in its portrayal of two mutually antagonistic communities and the banter between Mahmud and Lenny crackles nicely. Lenny describes himself as “a Buddhist Jew”, believing that you should “renounce all your possessions, but still keep the receipts”. The film, which features cameos from the likes of Matt Lucas, Tracy-Anne Oberman and David Schneider, works best as a sharp-edged comic exploration of the mistrust between Jews and Muslims, but fares less well when the plot surrounding the evil stepfather Arshad takes over.

Still, The Infidel is a timely attempt to get to the heart of its subject. Baddiel has insisted that he is not out to cause offence to either Muslims or Jews. “That doesn’t interest me as a writer. The film’s about race and culture and ethnicity, in a very gloves-off way,” he has said, adding that “the idea comes from a simple premise, which is that Jews and Muslims often look alike.”

Even so, it will be interesting to see how both communities react when the film is released on April 9.