The London mayor told Sky News today that “all the indicators” suggested stricter rules would need to be implemented in the city. He estimated that the current rate of infections was about 90 per 100,000 people.

Khan said he was “angry” with the government for having redeployed tests away from the capital, meaning there was a less accurate understanding of the transmission rate.

The five boroughs with the highest infection rates are Richmond, Hackney, Ealing, Redbridge and Harrow, but Khan said any measures should be applied across the whole of Greater London rather than to specific boroughs.

“Many Londoners work in one borough, live in another borough, study in another borough, go to a restaurant in another borough. So we’re really keen to go as one city,” he said.

“All the indicators I have: hospital admissions, ICU occupancy, the numbers of older people with cases, the prevalence of the disease, the positivity are all going the wrong direction. Which means, I’m afraid, it’s inevitable over the course of the next few days London will have passed a trigger point to be in the second tier.”

Prime minister Boris Johnson announced a new three-tier lockdown system yesterday.

London is currently under tier one, or medium, alert level. This includes the current national restrictions such as the “rule of six” and the 10pm curfew for pubs, bars and restaurants.

Tier two, or high alert, will see people prevented from socialising with other households indoors. However, people can mix outside in groups of a maximum of six.

The new alert system has been touted by many as too little too late. According to minutes from a 21 September meeting of the Scientific Advisory Group for Emergencies (SAGE), published last night, scientists called for a “circuit breaker” lockdown three weeks ago.

Other measures SAGE wanted to see considered included advice to work from home for all those that can, banning people mixing with other households, the closure of all bars, restaurants, cafes, indoor gyms and hairdressers, and for all university and college teaching to be online unless essential.