Social gatherings of more than six people will be illegal in England from Monday – with some exemptions – amid a steep rise in coronavirus cases.
A new legal limit will ban larger groups meeting anywhere socially indoors or outdoors, No 10 said.
But it will not apply to schools, workplaces or Covid-secure weddings, funerals and organised team sports.
It will be enforced through a £100 fine if people fail to comply with police, doubling up to a maximum of £3,200.
Several exemptions apply to the new rules – which come into force on 14 September – with households and support bubbles bigger than six people are unaffected.
A full list of exemptions will be published by the government later.
Prime Minister Boris Johnson is expected to deliver further details at a Downing Street news conference on Wednesday.
In a preview of his address, the PM said: “We need to act now to stop the virus spreading. So we are simplifying and strengthening the rules on social contact – making them easier to understand and for the police to enforce.
“It is absolutely critical that people now abide by these rules and remember the basics – washing your hands, covering your face, keeping space from others, and getting a test if you have symptoms.”
No 10 said any group of seven or more people gathering anywhere “risks being dispersed by police or fined for non-compliance”.