In what will be a blow to many industries, venues and couples, many events and re-openings that were due to take place tomorrow (August 1) will now not happen for another two weeks.
Indoor performances will not resume, pilots for introducing crowds to sports venues and conference centres will not take place, and wedding receptions of up to 30 people will not be permitted.
The Prime Minister announced the news in a Downing Street briefing this afternoon.
He said: "With those numbers creeping up, our assessment is that we should squeeze that brake pedal… in order to keep the virus under control.
"On Saturday August 1, you’ll remember we had hoped to reopen a number of the higher-risk settings that had remained closed and today I’m saying we’re postponing those changes for at least a fortnight.
"That means until August 15 at the earliest casinos, bowling alleys, skating rinks and the remaining close-contact services must remain closed.
"Indoor performances will not resume, pilots of larger gatherings in sports venues and conference centres will not take place, and wedding receptions of up to 30 people will not be permitted."
Face coverings are also to be mandatory in indoor settings where people are likely to come into contact with people they do not know, such as museums and places of worship from August 8.
While there is no change to work-from-home guidance from tomorrow, the PM promised to "come down hard" on workplaces which people do not feel are safe.
Speaking about the changes, Mr Johnson said it was right to respond to a "warning light on the dashboard".
"I’ve said throughout the pandemic that there would be fresh outbreaks," he said.
"I think from May I said – when we set out our plan – I said ‘we would not hesitate to put on the brakes at the slightest sign the numbers we’re going in the wrong direction’.
"We’re now seeing a warning light on the dashboard, it is right to respond in the way that we are."
Mr Johnson was asked what he would say to people who are apprehensive about returning to the office after home working, and he said: "I want to see people discussing with their employers whether they can work from home. Lots of people can work from home.
"A lot of people discover that it does work. But if employers think, and employees think, that actually to get in, to be productive, you need to be at your place of work then that’s a very, very important consideration.
"And it is safe to get into a Covid-secure workplace and people should understand that and that is our guidance."
Chief Medical Officer Prof Chris Whitty added: "But I think we should just be really grateful that huge numbers of employers have put an awful lot of effort into trying to make workplaces Covid-secure.
"It’s absolutely essential that everybody does that, but the great majority are, and then when that happens people stick to the guidance and the rules they’re given."
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