Boris Johnson is warning every household he could impose even stricter lockdown measures to tackle the coronavirus outbreak as it inevitably worsens.

The Prime Minister, who is self-isolating with Covid-19, is writing to every address telling people the closer they adhere to the rules “the sooner life can return to normal”.

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Stressing the “national emergency”, the letters will land on doorsteps after the number of people to have died in UK hospitals surged past 1,000, increasing by 260 in 24 hours.

NHS England’s national medical director warned that now was not the time for complacency after a study suggested social distancing could deliver a lower death toll than previously feared.

Scottish Secretary Alister Jack became the latest Cabinet minister to enter self-isolation with Covid-19 symptoms after the PM and Health Secretary Matt Hancock.

In letters to 30 million households, Mr Johnson writes: “We will not hesitate to go further if that is what the scientific and medical advice tells us we must do.

“We know things will get worse before they get better.

“But we are making the right preparations, and the more we all follow the rules, the fewer lives will be lost and the sooner life can return to normal.”

Mr Johnson last week offered a glimmer of hope when he said he expects the UK can “turn the tide” within three months, but a lengthier estimate for the lockdown was offered by a scientist whose research has been key in the Government’s approach.

Imperial College London’s Professor Neil Ferguson told the Sunday Times: “We’re going to have to keep these measures (the full lockdown) in place, in my view, for a significant period of time – probably until the end of May, maybe even early June.”

HEALTH Coronavirus(PA Graphics)

NHS England’s national medical director Professor Stephen Powis appeared at the daily press conference as Mr Johnson worked behind closed doors in his Downing Street flat.

Prof Powis warned the public not to rest on their laurels after an Imperial College London study suggested the UK could be on course for 5,700 deaths if it follows the same trajectory as China.

He said it would be a “good result” if the toll in the UK was less than 20,000, and stressed compliance with the strict rules, and not luck, would get the number down.

“But we shouldn’t be complacent about that, although that would be a good result, it will only happen if we stop the transmission of the virus,” he added.

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The nation learned that the number of coronavirus-related deaths in the UK had hit 1,019, as of 5pm on Friday.

Meanwhile, work was rapidly going ahead converting London’s ExCel convention centre into a field hospital dubbed the NHS Nightingale Hospital.

And to ensure hospitals can be sufficiently staffed, coronavirus tests were being trialled so frontline workers self-isolating with potential symptoms may be able to get the all clear and return to work.