Britain on Wednesday recorded its biggest day-on-day increase in coronavirus deaths, as the government came under renewed pressure to ramp up mass testing of frontline medical staff and the wider community.
The health ministry said 2,352 people had now died as of 1600 GMT on Tuesday -- up 563 on the previous day.
The number of confirmed cases of COVID-19 climbed by 4,324 to 29,474 in the same period.
Officials have warned Britain to expect a surge in cases in the coming weeks, saying that stringent social distancing measures could be working but will take time to have an effect.
Britain last Monday began a three-week lockdown, shutting non-essential shops and services to limit the close-contact spread of the virus and reduce the burden on health services.
Professional bodies have said absenteeism is currently high among doctors and nurses because many have been forced to stay at home after displaying symptoms or knowing someone who has.
Britain is currently focusing on testing people who are taken to hospital with severe symptoms, and there have been demands for all medical staff to be tested to see if they have had the virus.
Ministers have been put on the back foot over the lack of testing, with even media normally loyal to the governing Conservative party calling the situation a "shambles".
Britain has so far carried out a total of 153,000 tests, while Germany is testing 70,000 people a day. As of March 30, there were 455 deaths in Germany.
Prime Minister Boris Johnson, Health Secretary Matt Hancock and the heir to the throne, Prince Charles, have all tested positive for COVID-19.
Among the victims in Britain was a 13-year-old boy, whose family said had not displayed any other health condition.
Relatives of Ismail Mohamed Abdulwahab on Wednesday paid tribute to the "gentle and kind" teenager, and urged the wider public to "stay at home" to save lives.
- Kit shortages -
The health ministry said more than 10,000 tests for coronavirus were carried out on Tuesday in England, although it had capacity for almost 13,000.
The goal is to reach 25,000 a day by mid-April.
Johnson's spokesman on Wednesday said more than 2,000 staff in the state-run National Health Service (NHS) had been tested, adding: "We're very clear that we want more testing carried out."
Senior government minister Michael Gove has said the response had been hampered by a lack of "chemical reagents" needed for tests kits.
But the UK chemical industry has rejected the claim while the main opposition Labour party said the government needed to explain why there was such a difference with other countries.
"NHS staff are rightly asking if we've left it too late to buy the kits and chemicals we need, or whether our lab capacity is too overstretched after years of tight budgets," Labour's health spokesman Jonathan Ashworth said.
Britain's total of confirmed cases and deaths only cover hospital admissions.
The Office for National Statistics suggested on Tuesday the true death toll could be 24 percent higher, after analysing data for deaths in the community where COVID-19 is suspected.
Prince Charles, 71, meanwhile issued a video message after coming out of self-isolation on Tuesday, praising the "remarkable NHS" and urging people to be optimistic.
"None of us can say when this will end, but end it will," he said.
"Until it does, let us all try and live with hope and, with faith in ourselves and each other, look forward to better times to come."