In the run-up to last Saturday’s “Free Palestine” march, Metropolitan Police officers went out of their way to reassure the Jewish community that they would take a “zero tolerance” approach towards antisemitism on our streets. Those promises turn out to have been hollow.

The march — along with one organised by Hizb ut-Tahrir — was one of the most grotesque carnivals of Jew hate London has witnessed. It included calls for jihad and for Muslim armies to rise up. Pro-Hamas slogans were widespread, as was the chant of “From the river to the sea, Palestine will be free”, which is a demand for the elimination of Jews. The police made a few arrests, but seemed more interested in assisting activists by helping them down from the roofs of buses or holding their flags while they scaled buildings.

The Met’s social media account gave a running commentary on why it was refusing to act, with ever more bizarre reasoning. Explaining its inaction over the calls for jihad, it wrote: “The word has a number of meanings but we know the public will most commonly associate it with terrorism.” Well, yes. It went on: “Specialist officers have assessed the video and have not identified any offences arising.” What world does the police live in?

One possible explanation is that the Crown Prosecution Service has warned it would be difficult to secure convictions for acts like chanting “from the river to the sea”. CPS advisers were in the Met’s control room on Saturday.

But that cannot explain everything. Last week, police officers ordered a Campaign Against Antisemitism van highlighting the plight of the hostages to turn off its display so it didn’t aggravate the mob. The Met has talked tough, but at times like these, the Jewish community needs more than just words.