Asked about the rate of transmission within old people's homes, Sir Patrick Vallance says the average rate may be higher in "certain care settings".

He says it is "not entirely clear" what contribution that is making to the wider picture, but adds, "those numbers need to come down".

There's also a question on whether the UK has not recommended face masks for everyone because of fears it would lead to a shortage for healthcare workers.

Prof Chris Whitty, the UK government’s chief medical adviser, says this was "one of the reasons" the WHO advised against general mask use.

He says the evidence in favour of general mask-wearing is "weak", but the issue is being looked at again.

Some scientists and commentators have said the public will need to have social distancing measures in place until a vaccine is available.

Is that the case?

Prof Patrick Vallance says he "completely agrees" that vaccines and therapeutics are "critically important" when it comes to reducing the effects of this disease and reducing transmission.

He says the measures in the UK are needed now to get transmissions down to a low level, and "at that point, there may be decisions on which to relax and which not to relax".

Prof Vallance concedes there may be "a number of measures" that have to continue to allow the virus to be controlled until a vaccine comes along.

"But that is very different from saying the ones now need to be in place long term," he adds.

Nick Triggle
Health Correspondent

Professor Chris Whitty, the chief medical officer, stresses the “NHS is open for business”.

It is clear he is concerned people facing a medical emergency such as a heart attack, stroke or a flare-up of asthma are staying out of hospital during the crisis.

Visits to A&E have nearly halved since the outbreak began.

Foreign Secretary Dominic Raab is asked whether measures to protect people in care homes have been adequate.

"We're absolutely gripping this", he replies, adding that the health secretary set out a plan for the sector yesterday.

Asked about "excess deaths" indirectly related to coronavirus, Prof Chris Whitty says the UK will need to "take account of all of those".

He notes that economic deprivation can cause health problems in the long-term as well.

He says an analysis of the direct and indirect risks of the virus will be required when the lockdown is reviewed.

Nick Triggle
Health Correspondent

There's lots of talk about the R number - this is how many people an infected person passes the virus on to.

Without taking any measures, evidence suggests an infected person would pass the virus on to 2.5 people.

The fact it is now down to below one shows how effective the lockdown has been, and why Sir Patrick Vallance says the epidemic is decreasing.

The problem, of course, is that as soon as you lift the restrictions it will go up again.

A reporter says people from non-white backgrounds are very worried as there are reports they are worse affected by the virus.

Dominic Raab says the government is holding a review into the evidence, and is "on the side of anyone" hit by coronavirus.

Chief Medical Officer Chris Whitty says it is "critical" for them to find out which groups are most at risk so "we can protect them".

But, while it is clear the age of a person, if they have other diseases, and whether they are male can influence how badly they are affected, "being a member of an ethnic minority group is less clear".

Prof Whitty adds: "This is something we are very keen to get extremely clear. I have asked Public Health England to look at it in some detail... then we can look at what we can do next to minimise risk.

"But at this point in time, this is not yet clear."

Nick Triggle
Health Correspondent

Sir Patrick Vallance, the chief scientific officer, describes the slide showing the number of patients as the “critical slide”.

It shows that the number of people in hospital is falling – down 3% in the past 24 hours. The total number is below 20,000, which means there are still 10,000 beds available before the Nightingale field hospitals are taken into account.

The concern was that the NHS could be overwhelmed by the number of cases, repeating the distressing scenes in Italy earlier in the year.

So it is understandable that Sir Patrick calls it a “good place” to be.

The panel is asked why blood survey data to try to predict how many people have had the virus in the UK has not yet been published.

Prof Chris Whitty, the UK government’s chief medical adviser, says such surveys have been slowed down by lack of reliable tests.

He adds there is not yet a good "sampling frame" for the surveys, and it will take 21 days for data to be reliable.

He says "we are moving pretty fast" in scientific terms, adding a "crude ranging shot" may be available soon.

Asked by the BBC's Laura Kuenssberg about when the public can see the end of this, Dominic Raab refers to comments made by the prime minister at the beginning of the outbreak, saying this stage should last for three months.

"That is broadly still the outline [and] it will be reviewed at the end of the month," he says.

But he adds it would be "irresponsible" to give a definitive timeframe and could "prejudice the evidence" being collected by scientific advisers.

"There is light at the end of the tunnel, there is progress, and we must keep up."

Asked why he won't reveal plans for an exit strategy from social distancing measures, he again says it may prejudice the evidence.

"We have got to keep this up," says the foreign secretary. "What you are doing is working, notwithstanding the death toll - tragic for so many people.

"But if we let up now, it will be damaging for public health and the economy."

Image source, Downing Street

Sir Patrick Vallance, the UK’s chief scientific adviser, says it is "highly likely" the average person in the community is infecting one person or less - a so-called 'R rate' of less than 1.

He says this is an "important change," but cautions the rate may be higher in areas such as care homes.

Displaying the slide above, he says hospital admissions in Great Britain are declining and are "in a good place" - but says it is important to maintain the lockdown to keep this trend.

He adds that he expects the number of deaths to "reach a plateau" before it then begins to fall.

Nick Triggle
Health Correspondent

Interestingly, Dominc Raab set out criteria for the exit from lockdown – including “sustained and consistent fall in deaths” and confidence that the NHS could cope with a second peak.

It will be several weeks at least before the first is achieved. On the second, there is strong evidence to suggest we are probably there.

Cases in hospital appear to have peaked and there is still a reasonable amount of headroom – more than 10,000 hospital beds free and 2,000 intensive care beds and that’s before we take into account the network of NHS Nightingale units, with the exception of the 500 beds available in London.

The foreign secretary says he understands people have been comparing the UK's actions with other countries, but the government will "make decisions at the right time" for us.

He continues: "I appreciate the impact is considerable on people and businesses across the country.

"We get it, we know it is rough going. Every time I come to this lectern and read out the grim toll, I walk away and think of their sons and daughters going through this right now, their brothers, sisters, grandchildren, all those left behind.

"It makes this government focus even harder on what we must do and I know together, united, we must keep up this national effort."

Dominic Raab says he wants to be "up front with British people" about when the government can relax measures.

He lists five points that will influence the government's decision:

• Making sure the NHS can cope
• Evidence showing a sustained and consistent fall in daily death rates
• Reliable data showing the rate of infection is decreasing to manageable levels
• Being confident in the range of operational challenges, like ensuring testing and the right amount of PPE, are in hand
• Being confident any adjustments will not risk a second peak

Dominic Raab says there have been indications that social distancing measures in place are showing success.

But government advisers say the evidence is "mixed and inconsistent", and in some settings infections are increasing.

He adds: "We still don't have infection rates down as much as we need to.

"Any change to social distancing measures now would risk significant increase in infections," he says, as well as a second peak and an increase in the number of deaths.

As a result, the government will keep the current measures in place for three more weeks.

New York's lockdown measures will be extended until 15 May, the governor has said.

Andrew Cuomo said that experts would determine when the state could re-open. He said the decision would not be "political" or "emotional".

"Data and science. We're talking about human lives here," he said.

The UK's coronavirus lockdown measures will be extended for at least three more weeks, First Secretary of State Dominic Raab has announced.

Dominic Raab says: "Step by step, our action plan aims to slow the spread of the coronaviorus so fewer people need hospital treatment at any one time."

The Foreign Secretary says they have been following the science at every stage, and increased capacity for the NHS.

He confirms the number of deaths in the UK of those hospitalised with coronavirus has now reached 13,729 and pays tribute to them.

"They are heartbreaking losses for everyone affected," he adds.

Foreign Secretary Dominic Raab has taken his place inside Downing Street and this afternoon’s UK government press briefing is under way.

Stay with us and we’ll bring you all the latest updates here.

We should be hearing from the UK government in the next few minutes.

In the meantime, watch BBC journalists across the world explain the different items considered “essential” in other countries.

The UK government says it now has the capacity to carry out 35,000 coronavirus tests a day.

Earlier this month, England's Health Secretary, Matt Hancock, set a target of reaching 100,000 tests a day by the end of the month.

But halfway through April, the actual number being carried out was just over 15,500 a day.

The prime minister's official spokesman said this was due to a "lack of demand, not a lack of capacity", adding that the government was now expanding eligibility.

But the British Medical Association (BMA) said if the testing available wasn't being taken up, it was a matter of "communication and accessibility".

Image source, PA Media

Dr Chaand Nagpaul, the council chair at the BMA, said: "People need to know where and how they can be tested.

"The government must also ensure that it is accessible to all, including those in remote areas, those without cars and people with mobility issues.

“The government and NHS England must put greater effort into communicating how healthcare workers can take up this offer, so that dedicated staff can get back to work and save lives.”