Scotland Yard could deploy live facial recognition (LFR) technology at protests but revealed it was not used during Tommy Robinson’s anti-migrant march because the intelligence “didn’t justify it”.

The far-right activist led more than 100,000 people through Westminster on September 13 during his “Unite the Kingdom” rally.

Protesters clashed with the Metropolitan Police and hurled bottles, planks of wood and other missiles at them. Some 26 officers were injured during the “extremely horrifying spectacle”, and 26 arrests have been made.

Sir Sadiq Khan, the Mayor of London, condemned the violence and rejected the “appalling racism we saw on the capital’s streets” last weekend. He said: “I was shocked by the violence officers faced and I’ve been clear that was completely unacceptable.”

• Starmer condemns Unite the Kingdom rally: ‘It’s plastic patriotism’