The UK is facing its fourth week in lockdown, with the government set to review by Thursday whether social distancing measures can be changed.
Ministers are required by law to assess whether the rules are working, based on expert advice, after three weeks of telling Britons to stay at home.
It comes as an NHS boss has warned staff are facing a "hand-to-mouth" supply of protective gowns.
Meanwhile, the PM has thanked NHS staff after being discharged from hospital.
The mother of a nurse who Boris Johnson specifically praised said she was "exceptionally proud" of her daughter.
Wales' health minister said last week that the coronavirus lockdown would remain for "several more weeks at the very least".
And Scotland's First Minister Nicola Sturgeon warned there was "no likelihood or prospect" of measures being lifted after the Easter weekend.
On Sunday, the UK's total number of hospital deaths linked to coronavirus reached 10,612.
Chris Hopson, chief executive of NHS Providers in England which represents hospital trusts, told BBC Breakfast that the number of protective gowns - imported from China - available to NHS staff in some parts of the country has fallen "critically low" in recent days.
Mr Hopson said that the NHS ordered "a whole load of stock" weeks ago, but delays have been caused by the gowns sometimes failing safety tests, while other batches have been mislabelled - meaning the NHS has ended up with additional masks.
He added: "If everything had been flowing exactly as had been ordered and if all of the material had properly passed its safety test, there would not be an issue.
"This is all really hand-to-mouth in terms of gown delivery, and we need to get to a more sustainable supply."
Mr Johnson had spent a week at St Thomas' Hospital in London - including three nights in intensive care - where he was being treated for Covid-19, the disease caused by the coronavirus.
It is unclear whether the prime minister - who is now recuperating at Chequers, his country home in Buckinghamshire - will take part in the lockdown review.
In a video message to the nation recorded after he left hospital, 55-year-old Mr Johnson said it "could have gone either way" as he thanked NHS staff for saving his life.
He singled out two nurses - Jenny McGee from New Zealand and Luis Pitarma from Portugal - for caring for him at his bedside for 48 hours at the most critical time.
Foreign Secretary Dominic Raab is currently in charge of running the government, with aides reportedly expecting Mr Johnson to be out of action for as long as a month.
Asked how long it would be before Mr Johnson returned to work, Health Secretary Matt Hancock said it would be a "clinical decision for his doctors to take with him".
Speaking at the Downing Street briefing on Sunday, Mr Hancock insisted the government is "operating perfectly efficiently within the strategy that he set out."
Labour shadow cabinet minister Rachel Reeves said her party is calling on the government to publish its exit strategy for ending the lockdown.
Under the current rules, people are urged to stay at home and to only go out if they have a "reasonable excuse", which includes exercise, shopping for basic necessities, healthcare and essential travel to or from work.
Ms Reeves suggested ways of easing restrictions could include rolling out mass testing, shielding the most vulnerable while others get back to normal life and lifting the restrictions temporarily but reintroducing them if the virus starts to spread again.
"Although it's not the moment now to end the lockdown we need to think about where we are going to be in two, three, four weeks' time and now start looking at that plan," she told BBC Breakfast.
Speaking ahead of the Easter Bank holiday weekend, Mr Raab said it was still "too early" to lift lockdown restrictions, insisting they would need to stay in place until evidence showed the UK had moved beyond the peak of the virus.
But ministers may also have to consider any economic fallout of the lockdown measures, with a report by the National Institute of Economic and Social Research (NIESR) think-tank suggesting 25% of the UK economy could be lost by the summer due to the current controls in place.
Business Secretary Alok Sharma, when asked about the NIESR report, told the BBC's Andrew Marr Show there would "no doubt" be economic repercussions following the lockdown measures.
The BBC's political correspondent Ben Wright said it is expected that social distancing measures will be continued, but he added that "ministers are having to weigh up their responsibility to fight the disease with protecting the economy".
'A cruel disease'
Recently widowed Hannah - not her real name - has told how her husband of more than 40 years died after contracting coronavirus.
She told BBC Radio 4's Today programme that her husband was in hospital for about a week before he died, and was put on a CPAP machine, which delivers oxygen to the lungs without needing a ventilator, to aid his breathing during that time.
Describing his death, she said his breathing was "really laboured". "It is not a nice, quiet way to go," she said.
Hannah added: "This is such a cruel disease. Apart from the medical staff that he saw when he had to, [my husband] was alone for a week.
"I was alone at home, and I'm now alone at home. Nobody can give me a hug.
"My friends have rallied around, my church and everybody have been fabulous, but nobody can give me a hug.
"And I'm not lonely, I want to make that clear, I'm not lonely but I am alone."
On Sunday, 737 new coronavirus-related hospital deaths were recorded, taking the total number to 10,612.
Mr Hancock said it marked a "sombre day" for the nation, as it became the fifth country to surpass 10,000 deaths, joining the US, Spain, Italy and France.
Sir Jeremy Farrar, a member of the government's Scientific Advisory Group for Emergencies (Sage), said the UK was likely to be "one of the worst, if not the worst affected country in Europe".
The latest UK figures only include deaths recorded in hospitals, not those who died in care homes or in the community.
Sam Monaghan, the head of the UK's largest charity care provider MHA, told BBC Breakfast that about 150 of its residents had died with confirmed or suspected coronavirus, as well as two staff members.
He said the provider - which runs 90 care homes and 43 retirement living sites - was "somewhat in the dark" about the exact number of deaths, because not everyone who died was tested, although they may have been showing symptoms.
In other developments:
- The Post Office has extended its ask-a-friend scheme to allow people who may be shielding or self-isolating to authorise a trusted person to withdraw cash for them
- Mortuary suppliers have told BBC News they have no stocks of standard body bags left for sale, blaming stockpiling due to the coronavirus pandemic for the shortage
- Nearly 200 members of the armed forces are being deployed to help ambulance staff battle the coronavirus pandemic.
- Around 12% of firefighters and control room staff in some areas are self-isolating during the coronavirus pandemic, says the firefighters' union. The Fire Brigades Union (FBU) has called on the government to provide urgent coronavirus testing of its members so they can return to work
- The UK has confirmed plans for an app that will warn users if they have recently been in close proximity to someone suspected to have be infected by the coronavirus.
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