The statistical report published earlier this month by the Board of Deputies makes for interesting reading. The number of funerals carried out in 2010 under the auspices of any Anglo-Jewish religious authority fell again, thus confirming the trend of the past two decades.

By contrast, the number of Jewish births has risen. So British Jewry as a whole appears to have ceased contracting, and is probably growing. In 2007 - the latest year for which "inferred" data is available - the author of the report, Daniel Vulkan, calculates that there were 3,313 Jewish births. Again, this continues an upward trend. But Vulkan adds to this analysis some post-2007 data relating to what he terms the "strictly Orthodox" communities of Manchester, London and Gateshead; he concludes that "a conservative estimate would be that the strictly Orthodox community now accounts for 40 per cent or more of all Jewish births".

In 2010, the number of marriages performed under Anglo-Jewish religious auspices fell to 836 - the lowest figure since the Board's records began in 1901. "A consistent downwards trend … is now clearly identifiable," says Vulkan, adding that while, over the past 30 years, the proportion of marriages taking place under the auspices of "central Orthodox" synagogues (the United Synagogue and other synagogues of a similar orientation) has declined from almost two-thirds to just under a half, over the same period "marriages taking place in the strictly Orthodox community have increased from less than one in ten of the total to more than a quarter."

True to form, this intelligence was pounced upon by sundry spokespersons in the Charedi world. Dr Yaakov Wise, who predicted years ago that, by 2050, Charedim would constitute the majority of British Jewry, told the Jewish Tribune how pleased he was that the Board had "finally conceded the case." Rabbi Avraham Pinter, macher-in-chief of Stamford Hill, made public his amazement "that the Board can only begrudgingly say that the Charedi births are 40 per cent or more". What did he expect? A formal announcement from Westminster Hall, with fanfare from the Regimental Trumpeters of the Queen's Dragoon Guards?

Daniel Vulkan is obliged to "infer" the number of Jewish births because religion is not identified on any British birth certificate. He has used figures related to circumcisions and applied to these a "multiplier" - the ratio of male-to-female births in the general population. So far, so good - until we realise (and here I'm making a point favourable to the Charedim) that, in the Charedi world, unknown numbers of circumcisions are carried out by mohelim not registered with the Initiation Society.

Britain’s Charedim do not constitute one block

While I support Vulkan in using the "multiplier," I take issue with him over his reference to "the strictly Orthodox community". There is no such thing. Here, the conveniences of the demographer clash with the complex dynamics of Britain's Jewish citizenry.

The plain fact is that Britain's Charedim do not constitute a monolithic bloc. Here in north-west London, there are "black hats" who are - literally - refugees from Stamford Hill, forced to flee by subtle forms of religious persecution.

The plain fact is that, in north-west London, continuing controversy over the eruv has led to the formation of breakaway black-hat congregations.

There are black-hat Sephardim, black hats within my own Federation of Synagogues and even within the US. The Union of Orthodox Hebrew Congregations has recently placed advertisements urging Charedim to join its own burial society: such exhortations would have been unthinkable even a decade ago, and can only reflect the Union's morbid fear of a loss of "market share".

Not all Charedim are (in practice) Orthodox. Not all Orthodox are Charedim. We must also bear in mind that an increasing number of British Jews decline to identify with any communal organisation, just as we must remember that there is no agreement upon who is a Jew.

The reality is that the sectarian Anglo-Jewry over which Rabbi Pinter and Dr Wise exult constitutes merely part of a much more intricate and substantially larger whole.