England’s delayed reopening is a blow to culture and nightlife.

LONDON — Andrew Lloyd Webber last week promised to open his musical “Cinderella” in London’s West End on June 25 — even if it were illegal to do so.

“We are going to open come hell or high water,” he told The Daily Telegraph, a British newspaper. If Britain’s government tried to stop him because of rising coronavirus cases, he had one response, he added: “We will say: Come to the theater and arrest us.”

Now, Mr. Lloyd Webber, 73, has his chance to go to prison — although he doesn’t appear to want to take it.

On Monday evening, Prime Minister Boris Johnson of Britain said that social distancing would continue in England until July 19, at least — almost a month later than originally planned.

The decision, announced at a televised news conference, was made because of a rise in coronavirus cases linked to the Delta variant. An average of 7,278 cases per day were reported in United Kingdom in the last week, an increase of 127 percent from the average two weeks ago. Deaths are rising but still very low, with an average of nine a day over two weeks.

Scientists remain at odds over exactly how serious a threat it poses in Britain, however, with some arguing that the most dire predictions about rising hospitalizations underestimate the effect even the current level of vaccinations have on breaking the link between the number of new cases, hospitalizations and deaths.

“I think it’s sensible to wait just a little bit longer,” Mr. Johnson said, adding that the delay would allow more people to be fully vaccinated.

The delay was a gut punch to the British cultural world, which has been desperately seeking an end to social distancing.

The delay leaves “thousands of jobs hanging in the balance,” Julian Bird, chief executive of UK Theater, a trade body, said in a statement. A quarter of nighttime businesses cannot survive longer than a month without new government support, the Night Times Industries Association, which represents clubs and pubs, said in a news release.

The biggest blow may be to England’s nightclubs, which were told for the fourth time that they could not reopen at all, even with distancing. Nightclubs in Britain have been closed since March 2020, and over 150 events were planned in London alone for the weekend of June 25, including a sold-out 42-hour-long party at Fabric, a famed club that can hold 1,500 people.

Those were all immediately canceled.

“It’s really, really frustrating,” Cameron Leslie, one of Fabric’s founders, said in a telephone interview. He had hired over 100 staff over the past month, expecting to reopen, and now was not able to furlough them.

“You can only be pushed and tested so far before our entire sector can’t respond anymore,” Leslie added.

Stuart Glen, the founder of The Cause, another London club, said in a telephone interview that the delay would cost him “hundred of thousands” of pounds and force him to rearrange 40 events. He’d had enough, he said. “I think everyone should riot if July doesn’t happen,” he said. “They can’t control people like this,” he added.

“It’s so devastating for so many people,” said Yousef Zahar, a D.J. and co-owner of Circus, a nightclub based in Liverpool, that in May held two pilot events featuring 6,000 maskless dancers.

Theaters, museums and music venues were allowed to reopen with distancing last month, but larger venues and all nightclubs have remained firmly shut. Mr. Lloyd Webber has repeatedly said that glitzy productions like “Cinderella” — which has a 34-strong cast and is already weeks into rehearsals — are financially unviable in half-full theaters.

For those hoping to attend the opening of“Cinderella,” it was still unclear if the show would go on.

“We’re working hard behind the scenes to make sure everyone gets to the ball,” the show’s producers said in a statement posted on Twitter.