Dame Cressida Dick, the Metropolitan Police's Commissioner, said that while the number of referrals to Prevent, an anti-radicalisation scheme, fell by half during the first lockdown in 2020, they have now risen to higher than usual levels and law enforcement have "a record level of casework".
She said: "Covid-19 has created an environment, in the UK certainly, in which extremists may find it easier to identify and target and potentially radicalise vulnerable people.
"It has done so by exacerbating pre-existing inequalities, by stoking distrust in authority, and inspiring a new wave of conspiracy theories that have more easily reached the mainstream.
"Not only that, but longer term impacts such as unemployment and financial uncertainty caused or exacerbated by the pandemic are exactly the problems in people's lives that extremists can latch on to when they are looking to radicalise.
"If you add to that the increased social isolation people have endured over the last 18 months and a reduction in support services such as mental health provision and social care during the long periods of so-called lockdown, that is a potent mix which is of real concern."