Boris Johnson confirmed the changes will take effect from Monday, 14 September and that gatherings of more than six people will be illegal. Currently, the lawful limit on gatherings is 30 people.
The chief medical officer, Professor Chris Whitty, and chief scientific adviser, Sir Patrick Vallance, have agreed urgent action is needed after the number of positive cases rose steeply.
In a Zoom meeting with the prime minister last week, police forces said they would like rules on social contact to be simplified.
Where will they apply to?
The rules will apply across England to all ages and to indoor and outdoor gatherings. This will include private homes, parks, pubs, cafes and restaurants.
This means, for example, that you cannot sit at a pub or restaurant table with more than five people at any given time.
Full guidance on what can and cannot happen is expected to be issued before Monday.
Will there be any exemptions?
There will be a few scenarios where the restrictions do not apply, such as if your household or support bubble is larger than six people, or if you are gathering in a large group for work or education.
Weddings, funerals and organised team sports will also be exempt if they are conducted in a Covid-secure way.
Households or bubbles of more than six people will be able to gather in public and private settings but will not be able to mix with other groups.
What will the penalty be for breaking the rules?
The government hopes the new rules will make it easier for the police to break up large gatherings.
Failure to stick to the new rules could mean a £100 fine, which will double with every subsequent offence up to £3,200.
What has Boris Johnson said?
The prime minister officially announced the new rules at a press conference on Wednesday and urged people to follow them to avoid a second national lockdown.
He admitted the rules had become too complicated and said it was time to simplify restrictions: “This single measure replaces both the existing ban on gatherings of more than 30 and the current guidance on allowing two households to meet indoors. Now you only need to remember the rule of six.”
Johnson also emphasised the importance of regular hand-washing, wearing face coverings and maintaining social distancing.
What are the rules in other parts of the UK?
Up to eight people from three different households are allowed to meet indoors, while groups of 15 from up to five households are permitted outdoors – but people should maintain a safe distance.
Outdoors, a maximum of 30 people are allowed to meet. Indoors, up to four households can form what’s called an extended bubble.
The most people who can meet outdoors is 15. Indoors, six people from two households can meet.
How can we be socialising safely?
A new campaign has been launched to encourage people to help stop the spread of coronavirus as we are more likely to socialise indoors during the autumn and the winter.
The “Hands, Face, Space” campaign urges people to ensure they have washed their hands, used a mask where appropriate and maintain social distancing.
The campaign states that these are the three most effective ways the public can contain the spread of the virus.
This article originally appeared on HuffPost UK and has been updated.