Social gatherings of more than six people will be illegal in England from Monday - with some exemptions - amid a steep rise in coronavirus cases.
The law change will ban larger groups meeting anywhere socially indoors or outdoors, the government 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, doubling on each offence up to a maximum of £3,200.
The new rules - which come into force on 14 September - mark a change to England's current guidance.
At present, the guidance says two households of any size are allowed to meet indoors or outdoors, or up to six people from different households outdoors. Until now the police have had no powers to stop gatherings unless they exceeded 30.
Prime Minister Boris Johnson is expected to give further details of the changes at a Downing Street news conference later on Wednesday.
"One of the pieces of feedback we had including from the police was that we needed the rules to be super simple so that everybody knows what they are," said Health Secretary Matt Hancock.
"And now this will now be rigorously enforced by the police."
Mr Hancock told BBC Breakfast: "This is really simple. Gatherings are ok, they should be socially distanced of course, but groups only of up to six."
He said it means that some families will not be able to see both grandparents at the same time. "You know, I have three children," he said. "We have a family of five. And so we'll be able to see one other person at a time, as a whole family."
Read the full news story here: https://www.bbc.co.uk/news/uk-54081131#