Antisemitic incidents almost doubled in one of the country's most Jewish populated boroughs in 2015, according to police figures.
There were 122 reports of such incidents in Hackney, the area of north-east London which is home to Britain's largest strictly Orthodox community, in the year from November 2014.
The figures equate to an 88 per cent increase in reported antisemitic episodes - there had been 65 reported cases in the previous 12-month period.
Across the capital the Metropolitan Police reported a total of 483 antisemitic crimes, up from 299 incidents the year before.
Rabbi Herschel Gluck, president of the Stamford Hill branch of Shomrim, the community's volunteer security group, said the steep rise demonstrated "the depth and persistence of this grave problem" and the urgent need to deal with it.
Hackney police said the group had "played a huge part" in assisting officers in tackling antisemitism in the area.
In north-west London, Shomrim's telephone hotline received more than 3,200 calls in 2015.