A new ban on groups of more that six people is to be announced and will become law on Monday.
Under the ban, the gathering of groups of more than six people in homes, pubs, parks, restaurants and clubs will become illegal.
The ban is in response to a spike in Covid-19 infections believed to have been caused in large part by young people becoming complacent.
First time breeches of the ban will be met with a fine of £100. Fines will double for each subsequent repeat offence up to a total of £3,200.
The Prime Minister will say:
"We need to act now to stop the virus spreading,"
Mr Johnson will announce the new ban at a Downing Street news conference coinciding with the launch of a new government advertising campaign entitled "Hands. Face. Space." He will also say:
"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 symptom."