Boris Johnson has returned to Downing Street to take charge of the UK's response to the coronavirus outbreak.
The prime minister will chair the regular morning cabinet meeting on Covid-19 before holding talks with senior ministers and officials.
He arrived back at No 10 on Sunday evening amid mounting pressure from Tory MPs to begin lifting the lockdown.
But Health Minister Edward Argar said "now is not the time to ease up" even if people were feeling frustrated.
The latest official figures bring the total number of deaths in UK hospitals to 20,732, after a further 413 were announced on Sunday.
It is a month since Mr Johnson was diagnosed with the virus. He spent a week in St Thomas' Hospital in central London, including three nights in intensive care, after being admitted on 5 April.
Mr Johnson has not been doing any official government work during his convalescence at his country residence, Chequers, although last week he did speak to the Queen and US President Donald Trump, as well as meeting senior ministers.
He will now resume full-time duties, although it is unclear at this stage whether he will lead Monday's press briefing.
BBC assistant political editor Norman Smith said he thought it would be "extraordinary" if Boris Johnson's own coronavirus experience had not shaped his views on "how lethal" the virus is.
The public debate around easing the lockdown could "begin in the next few days", he added, but we are "still some way off getting any easing of the lockdown".
Lockdown review next week
Strict limits on daily life - such as requiring people to stay at home, shutting many businesses and preventing gatherings of more than two people - were introduced on 23 March, as the government tried to limit the spread of the virus.
Ministers are required by law to assess whether the rules are working, based on expert advice, every three weeks. The next review is due by next Thursday 7 May.
Our correspondent Norman Smith added Mr Johnson will need to "convince people ahead of then" that the government's approach is the right way to go.
Speaking to BBC Breakfast, Mr Argar said he could "understand the frustration people are having with these measures".
He said there had been much press "speculation" about when the lockdown might end, but: "The reality is we're not there yet.
"We're not in a place where the science says it is safe to ease the restrictions. We need to keep these in place to keep that infection under control, and not to lose the gains we've all made."
Avoiding second wave is top of PM's list
There are a huge range of decisions facing Boris Johnson after a race in government in the last month or so to keep up with the demands of this crisis.
The biggest collection of decisions though is how and when to start the move out of the lockdown that Boris Johnson brought in from a desk in Downing Street on 23 March.
In cabinet of course, there are different tones, different emphases. The Treasury, for example, is focused on the profound economic harm, eager to know the timetable of when restrictions might start to ease off.
They all of course want to minimise the loss of life but, as you'd expect, the Department of Health is particularly concerned about how the NHS is coping.
And, of course, if there were to be a second wave, what would happen in that kind of circumstance?
It is clear the prime minister himself sees the prevention of a second deadly spike, which could be worse than the first, to be the absolute top of the list.
But I don't think this is a question of either you prioritise people's health or you prioritise the nation's wealth.
It is an almost impossible balancing act.
And partly for that reason, I don't think there will be any big moves of substance this week.
Sir Graham Brady, chairman of the Conservative backbench 1922 committee, said there was a limit to how long people would tolerate restrictions.
He said: "If there is a question over whether something is necessary or not, I think we should err on the side of openness and trying to make sure that more people can get on with their lives and more people can get on with getting back to their jobs."
Frances O'Grady, head of the umbrella group for unions the Trades Union Congress (TUC), said when people do return to work, social distancing should continue, along with risk assessments in every workplace, staggered shifts and safe transport.
Foreign Secretary Dominic Raab, who has been standing in for the PM, said on Sunday that social distancing would remain for "some time" in the UK.
Rather than a complete lifting of all measures, he said the country would end up "moving to a new normal".
He suggested social distancing measures already being seen in food shops and other businesses that have remained operating could also be expanded to non-essential businesses if they were to reopen.
Labour's Rachel Reeves said the UK should "potentially" be following the example of countries like Belgium, Germany and Denmark which have already signalled partial re-opening of some businesses and schools.
"We want to work with the government in bringing forward a plan and getting it right," she said.
Scientists advising the government have warned any relaxation risks a renewed flare-up just as the numbers of patients in hospital with the disease is beginning to fall.
NHS England medical director Professor Stephen Powis told the daily No 10 briefing: "My fear is that those curves won't continue to be on a downward trend, but will start to go on an upward trend.
"We are not at a point where any of us can be absolutely confident that that's not going to be the case."
A further 413 coronavirus deaths in UK hospitals were announced on Sunday - the lowest number that has been reported in April.
However, experts have previously warned against over-interpreting daily statistics, as they often reflect reporting delays, particularly over weekends - so do not relate directly to the number of deaths that occurred on a certain day.
Meanwhile, Mr Raab insisted the government remained "on track" to hit its target of carrying out 100,000 tests for coronavirus per day by Thursday.
There were 29,058 tests carried out on Saturday, far short of the government's target - which it aimed to achieve by the end of April.
Environment Secretary George Eustice said the capacity for testing had risen to more than 50,000 a day, adding that "significant numbers" of people in care homes were obtaining tests.
Since Friday, millions of key workers and people they live with have been able to book appointments online to be tested.
However, the British Medical Association said testing for healthcare staff should not be on a "first come, first served" basis after slots ran out for the third day in a row.
Appointments to visit a test site in England ran out about seven hours after the website opened on Sunday, much later than in the previous two days.
Spaces remained available in Scotland throughout the day. Key workers in Wales and Northern Ireland cannot currently book tests online.
Those too ill to travel should also be able to order home kits - although numbers are limited. On Sunday morning home kits were no longer available within 15 minutes of the site reopening at 08:00 BST.