Millions of Londoners will be prevented from socialising with other households indoors after midnight on Friday as the capital has passed the ‘trigger point’ to go from ‘Tier 1’ to the tougher ‘Tier 2’.

However, people will still be able to mix outside in groups of a maximum of six.

The health secretary, Matt Hancock, gave a speech in the Commons, where he said infection rates are on a steep upward path, with the number of cases doubling every 10 days. The seven-day average case rate today stands at 97, rising sharply.

He said: “Working with the Mayor, cross-party council leadership, local public health officials and the national team, we have together agreed that London needs to move to local Covid alert level high.

“We now all need to play our part in getting under control once again.

“I know the sacrifices this means. But I know, if we work together, then we can defeat this.

“Working with local leaders in Essex and Elmbridge, we are also moving them to the high local alert level.”

He added that cases in Barrow-in-Funess, York, North East Derbyshire, Erewash and Chesterfield have also doubled in the past two weeks and they will also enter the high alert level which comes into effect one minute past midnight on Saturday morning.

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

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.

However, just a couple of days ago, London mayor, Sadiq Khan told Sky News that “all the indicators” suggested stricter rules would need to be implemented in the city within the next few days. He estimated that the current rate of infections was about 90 per 100,000 people.

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

Liverpool was categorised in ‘Tier 3’ (very high alert level) this week which prohibits social mixing indoors and in private gardens, with the rule of six allowed in open public spaces like parks and beaches.

Pubs and bars must close, and can only remain open where they operate as if they were a restaurant – which means serving ‘substantial meals’, like a main lunchtime or evening meal. They may only serve alcohol as part of such a meal.

Reports suggest Greater Manchester is set to join Liverpool in this category.

For anyone flouting the rules, you can be fined £200 for a first offence which can double for further offences up to a maximum of £6,400. If you hold, or are involved in holding, an illegal gathering of over 30 people, the police can issue fines of £10,000.