The number of people being admitted to hospital with coronavirus is falling - but it's too early to tell whether the lockdown can be lifted, experts say.
Dame Angela McLean, deputy chief scientific adviser, said the drastic measure - now in its third week - appeared to be working.
She said Covid-19 hospital admissions seem to be falling, but added: "It really is too soon to see the effects of the huge changes we've made to our lives."
And England's Chief Medical Officer, Prof Chris Whitty, said it is still not clear whether the epidemic's peak will be at the end of the week, warning it is "too early" to tell when restrictions can be lifted.
Foreign Secretary Dominic Raab said the Government's top priority remains to "stop the spread and make sure we can get past the peak" - suggesting there is no imminent end to the lockdown being considered.
Mr Raab stressed that Boris Johnson - who is being treated in hospital after being infected with the killer bug - remains in control of the government.
But he conceded that he has not spoken to the PM since Saturday.
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At the moment, Mr Raab said the focus is still on maintaining strict measures to slow down the rate of infections.
When quizzed about what the Government's "exit strategy", he said: "The risk right now is if we take our focus off the strategy which is beginning to work, we won't get through the peak as fast as we need to, which is why it's perfectly legitimate to ask the question.
"But the Government's over-riding priority has got to be to keep up the work and the commitment that so many people have made to make sure that we maintain the social distancing, we stop the spread, we protect the NHS as we come through the peak."
And Dame Angela said hospital admissions data by region had risen "very steadily" until April 1 - and then showed a "more complicated behaviour, starting we hope to slow down".
She continued: "We need a good, long time series of data on all of these stages of infection in order to be able to tell what the impact of the measures that came on March 23 are going to be.
"It's too early to tell yet, we need people to carry on following those instructions so that we can work out three weeks later what actually happens in hospitals."
Boris Johnson continues to lead the government from his hospital bed and is in good spirits, Mr Raab said.
The Prime Minister was last night hospitalised as his Covid-19 symptoms persisted.
Mr Raab said Mr Johnson was being "kept abreast" of developments.
Pressed on why Mr Johnson is sick enough to be in hospital but well enough to be running the country, Mr Raab said: "That's something he will decide on the medical advice he's received from his doctor."
Mr Raab said that the Prime Minister's team are "full throttle" in making sure that his directions and instructions are being implemented whilst he is in hospital.
He said: "Look, he's (Mr Johnson) in charge, but he'll continue to take doctors' advice on what to do next."
Mr Johnson is being kept in hospital for observation after the official description of his symptoms shifted from "mild" to "persistent".
Today the death toll rose to 5,375, an increase of 441 in 24 hours.
Prof Whitty said it was "critical" for the NHS to always have an excess of available critical care beds during the fight against coronavirus.
He told the press briefing: "Our principle aim... is to ensure the gap between the number beds available for intensive care and those that are needed is always in a situation where we have some room to spare.
"And if we end up in a situation where we have more ICU beds at all times during this epidemic than we absolutely need to deal with Covid and other areas, that will be a success.
"That is something which is critical for our overall aim. What we would like to see is some headroom between what we need and what we have available at any given time, both for Covid and other conditions."
Downing Street earlier declined to say explicitly whether or not the Prime Minister has pneumonia.
No10 did, however, say Russian reports that Mr Johnson was on a ventilator are "disinformation".
Mr Raab was joined by England's Chief Medical Officer, who has himself been self-isolating after developing Covid-19 symptoms.
The Foreign Secretary chaired the daily government coronavirus meeting.
However, the PM's spokesman said that he had received his ministerial red box containing his official papers and was continuing to work from hospital.
"He continues to receive a box. The Prime Minister remains in charge of the Government."
