Mayor Sadiq Khan announced the review would be carried out by Lord Harris, who in an earlier report made 100 recommendations on how to boost the capital’s safety and its response to terrorist incidents.
The 2016 Preparedness Review was compiled following marauding firearms and lorry attacks at the Bataclan in Paris, and in Brussels and Nice.
Since then, Britain has been hit by a series of terrorism incidents, particularly in 2017 in London and Manchester, often by individuals acting alone, and there was the chemical weapons attack in Salisbury in 2018.
The review will consider emerging threats, including from the Covid pandemic which has left many people isolated and vulnerable to radicalisation online.
Mr Khan said: “The attacks on our city in 2017, the Manchester Arena bombing and, more recently, the attacks in Streatham and at Fishmongers’ Hall, means there’s much more to be learned.”
City Hall stressed that after the earlier Harris Review, there had been “significant improvements” to the speed and co-ordination between the emergency services, intelligence agencies and other key organisations in response to terrorist incidents.