Never has it been truer that you find out who your real friends are when you actually need them. And never has a self-proclaimed friend turned out to be less of one than Sadiq Khan.

During his victorious campaign for the London mayoralty in 2016, Khan visited shuls regularly and even started his Ramadan fast at one. He told this paper: “What’s important to me is that we have zero tolerance of antisemitism. I will ensure there are sufficient police resources and the resources of City Hall to address this issue.” Khan’s first public engagement as mayor was a Yom HaShoah ceremony at the Barnet Copthall Stadium in north London.

In his seven years as mayor he has carried on in the same vein with fine words and gestures. He has repeatedly stressed his credentials as an ally of the Jewish community. The visits have continued and so has the schmooze.

Well, guess what. Now that we actually need an ally as mayor of one of the world’s greatest cities - now that Jews have been slaughtered in the worst massacre since the Holocaust and antisemitism is rising exponentially – not only has Khan been absent from the fray, he has been worse than useless.

His claims about zero tolerance of antisemitism should embarrass him, when the police’s sole contribution to the two demos in London has been to stand and watch while the streets have seen chants of “From the river to the sea” – a call for the elimination of Jews – as well as calls for jihad and for Muslim armies to rise up, along with signs that would have fitted in at Nuremburg. And all we have heard from Khan has been a few bland statements and the odd social media post, with not a word of outright condemnation of the festival of Jew hate on the streets of his city.

With hindsight, if that had been the worst of it – that he had gone missing in action – then we would have seen his previous blandishments as no more than usual political warm words, which any sensible person dismisses. The political campaigning equivalent, as it were, of Sam Goldwyn’s line that a verbal contract isn't worth the paper it's written on.

But that’s not the worst of it.

Today, the mayor has issued his most detailed and lengthy statement, in a video. It contains the now pro forma words that every mainstream politician feels obliged to say, that Israel has a right to defend itself, to target those responsible for the terror attack to take action to free the hostages. But all of that is rendered meaningless by the sole purpose of the slogan plastered over the video: “I’m joining calls for a ceasefire”.

As I said, now we learn who our friends are. Not once in his two and a half minute video does he consider it worth uttering the word ‘Hamas’. Not once.

Instead, he demands that the Israelis stop all military action against the terrorist group that butchered 1400 people. The RAF and our allies killed 11,000 civilians when we went after ISIS in Mosul. Did Khan demand a ceasefire then? Can you imagine if a terrorist group had killed 1400 Londoners (or, God forbid, 9000 – which would be the equivalent in terms of relative population of Israel and the UK) and, with thousands of rockets still falling over London from the group responsible, the mayor of London then decided to call for a ceasefire? He would not survive the day in office.

But it’s only dead Jews, so who cares.

Be clear about this. Khan has shown that he is no friend of London’s Jewish community. Indeed, at the very moment when we need an ally – when, as the chief rabbi put it yesterday, we are more concerned about our future and safety than at any point since 1945 – he is demanding that the Jewish state stop defending itself against terror.

I am sure that in the run up to next year’s mayoral election this has nothing to do with  the fact that 15 per cent of London voters are Muslim as opposed to 1.6 per cent who are Jewish. Of course not.

What a contrast with the mayor of NYC, who has been ever present, vocal and clear in his support for and allyship with his city’s Jewish community and the need for Israel to destroy Hamas. Instead, we are left with a moral vacuum – a man who speaks of his friendship but acts as the very opposite.

Shame on you, Sadiq Khan. Shame on you.