Coronavirus has changed everything. Make sense of it all with the Waugh Zone, our evening politics briefing. Sign up now.
It came as Chris Whitty, the chief medical officer, warned the country had “probably reached the limits of what we can do in terms of opening up as a society”.
Johnson’s decision means venues including bowling alleys, skating rinks and casinos will now not be allowed to reopen tomorrow as planned.
Other venues affected include indoor performances to a live audience, such as theatres, and pilot schemes with socially distanced events in places like sports stadiums.
Wedding receptions for up to 30 people will also now not be allowed to take place as hoped.
But shielding will still end as planned tomorrow, and Johnson said people should still return to work if possible.
Speaking at a press conference in Downing Street on Friday, the prime minister said lifting these restrictions would be delayed until August 15 at the earliest.
Johnson said that despite progress being made in combating Covid-19, the UK cannot think it is exempt from a rise in cases and he had to “squeeze the brake pedal in order to keep the virus under control”.
“I’ve also consistently warned that this virus could come back and that we would not hesitate to take swift and decisive action as required,” he said.
“I’m afraid that in parts of Asia and in Latin America, the virus is gathering pace and some of our European friends are also struggling to keep it under control.
“As we see these rises around the world, we can’t fool ourselves that we are exempt. We must be willing to react to the first signs of trouble.”
Whitty said: “The idea that we can open up everything is clearly wrong. Choices will need to be made.”
The move came as the Office for National Statistics (ONS) said there had been an increase in the number of people testing positive for coronavirus in England.
According to the ONS, between July 20 and 26 there were around 0.78 new Covid-19 infections for every 10,000 people in the community population in England.
This is equal to around 4,200 new cases per day. This is up from an estimated 2,800 new cases a day in the previous week.