Scotland Yard Assistant Commissioner Mark Rowley, the National Policing Lead for Counter Terrorism, revealed that there were 327 arrests in 2014 for terrorist offences – up by 32 per cent since 2013.

In a briefing given after last week’s attacks in Paris, Mr Rowley said the “global picture” of extremist activity had raised serious concerns for the safety of the UK’s Jewish community, with “continuing anti-Semitic rhetoric” emerging.