The Institute for Jewish Policy Research (JPR) has issued a correction on the number of Anglo-Jewish births, making clear the increase in babies born outside the Charedi community is far less than stated in a report it originally published last week.

While the initial report, which received widespread media coverage, said non-Charedi births had risen by more than 19 per cent from 2007 to 2015 — compared to 35 per cent for Charedi births — the adjusted mainstream figure is much lower, with a rise of just 2.4 per cent.

The confusion arose because JPR was using more than one database to calculate Jewish birthrates.

JPR — which published the report on “vital statistics” with the Board of Deputies — admitted the error and issued revised figures on Monday after the JC pointed out the original numbers had been incorrectly calculated.

Jonathan Boyd, executive director of JPR, said: “Published data on births in the Jewish population have always been based on circumcision data from mohalim, in full knowledge that not all Jewish children are circumcised by mohalim, or indeed, at all.

“For the first time in this study, we were able to estimate the extent to which non-circumcision, or circumcision in hospitals (not by mohalim) affect the overall counts, but an error was made when reconciling data from different datasets.

“We have seen a small increase in births in the mainstream sector over the period shown, but not at the levels originally reported.”

According to the organisation, the overall births for British Jewry in 2015 remains at 3,821 for the year 2015.

The figure is based on the number of circumcisions performed by Orthodox and Progressive mohelim: the proportion of male to female births for the general population is then used to calculate overall births.

JPR estimates the 3,821 figure is made up of 1,932 Charedi births and 1,889 non-Charedi — indicating a majority of religious circumcisions in 2015 were Charedi (50.6 per cent). The original report, however, gave a figure of 2,199 for “mainstream” births.

But the report goes on to suggest that the figure underestimates the number of births outside the Charedi community. According to JPR’s survey of British Jewry in 2013, nearly a quarter of Jews do not have their children religiously circumcised: eight per cent have a non-religious circumcision in hospital, while 16 per cent do not circumcise their sons at all.

If these are taken into account, then the number of estimated mainstream births rises from 1,889 to 2,485 and the proportion of Charedi births drops to 43.7 per cent.

The total of Anglo-Jewish births in 2015 rises from 3,821 to 4,417.