LONDON (AP) — The British government announced Thursday that a nationwide lockdown imposed to slow the spread of the new coronavirus will remain in place for at least three more weeks, as health officials said the U.K.’s outbreak — one of Europe’s worst — was nearing its peak.

The lockdown has been in place since March 23. Schools, pubs, restaurants and most shops are closed, and most people are allowed to leave home only for essential errands or exercise.

“We know it’s rough going at this time,” said Foreign Secretary Dominic Raab, who is standing in for Prime Minister Boris Johnson as the British leader recovers from COVID-19.

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But, Raab said, “we’ve sacrificed far too much to ease up now.”

“There is light at the end of the tunnel, but now we are at both a delicate and dangerous stage in this pandemic,” he said at a news conference.

Medical officials say the number of new cases and hospitalizations for the coronavirus in the U.K. has leveled off, but it’s too early to loosen restrictions on daily life.

Chief Scientific Adviser Patrick Vallance said that while transmission of the virus has been dramatically reduced, “we run the risk of a second peak” if the lockdown is loosened now.

As of Thursday, 13,729 people had died in U.K. hospitals after testing positive for coronavirus, an increase of 861 from a day earlier. That number understates the true toll of the pandemic, since it does not include hundreds, and maybe thousands, of virus-related deaths in nursing homes and other settings.

For now, extending the lockdown has wide public and political support. But as other European countries cautiously ease their restrictions, Britain’s Conservative government faces pressure to explain when and how the country will reopen.

Raab gave no indication of whether any lifting of the restrictions was likely at the end of three weeks — May 7, the eve of a holiday long weekend in Britain. He said the decision would be based on factors including a sustained fall in daily deaths and evidence the rate of infection was down to “manageable levels.”

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Raab said that if those conditions were satisfied the measures could be adjusted to allow “some economic and social activity to resume.”

“It could involve relaxing measures in some areas while strengthening measures in other areas,” he said.

The suspension of normal business activity has thrown hundreds of thousands of Britons out of work and sent the economy into a nosedive. The Office for National Statistics said Thursday that a quarter of U.K. businesses had temporarily closed since the lockdown began.

The Conservative government’s response to the pandemic has been complicated by the absence of Johnson, who has not returned to work after spending a week in a London hospital being treated for COVID-19. The government is wary of making big decisions until he is back.

Epidemiologist Neil Ferguson, a government adviser, said “significant” social distancing will have to be maintained until there is a vaccine for the coronavirus — a development that could be over a year away.

He said easing restrictions would also require vastly expanded testing for the virus, so that people who are ill, and their contacts, can be isolated or quarantined.

Ferguson said without broad testing “we have relatively little leeway.”

“If we relax measures too much, then we’ll see a resurgence of transmission,” he told the BBC. “What we really need is the ability to put something in their place.”

Britain’s government has been criticized for its belated response to the pandemic, including limited testing and delays in getting protective equipment to health care workers.

The government insists it is rectifying those mistakes. It has vowed to conduct 100,000 tests a day by the end of April — a more than five-fold increase on current rates.

Critics have also accused U.K. officials of unnecessary secrecy over pandemic planning. The government’s decisions are based on advice from the Scientific Advisory Group for Emergencies, a panel of scientists whose full membership list has not been made public.

The British government also is accused of neglecting nursing home employees and residents. Virus-related deaths at nursing homes or any other non-hospital setting are not included in the government’s daily tallies. The Office for National Statistics said up to April 3 this year, 383 deaths involving COVID-19 occurred outside hospitals.

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In a leaked letter, nursing home bosses have accused the government of offering conflicting messages, creating confusion and adding to the workload of those on the front lines.

The letter from the Association of Directors of Adult Social Services, published by the BBC, said the distribution of protective equipment had been “shambolic.”

Association President Julie Ogley said she regretted the leak of the letter but not its contents.

“Some of the language used in the letter may be more emotional than we would normally use, but we are in emotional times,” she said.