The NHS in England will get an extra £3bn of funding to prepare for a possible second wave of coronavirus, Boris Johnson has announced.
The funding will also help ease winter pressures on the health service, Downing Street said.
It follows warnings a second wave this winter could see around 120,000 Covid-19 deaths in UK hospitals.
The PM made the funding commitment at a Downing Street briefing, where he also pledged a new testing target.
Under the plans, capacity will be increased to at least 500,000 tests a day by the end of October, Prime Minister Boris Johnson said.
Mr Johnson will also publish an additional chapter to the government's Covid-19 recovery strategy "roadmap".
A call with cabinet members to sign off the plan will take place on Friday morning.
Meanwhile, Health Secretary Matt Hancock has called for an urgent review into how coronavirus deaths have been recorded in England.
Downing Street said the new NHS funding would be available immediately and would allow the NHS to continue using additional private hospital capacity and maintain the temporary Nightingale hospitals until the end of March 2021.
This will provide additional capacity for coronavirus patients, as well as allowing the NHS to carry out routine treatments and procedures, No 10 said.
Non-urgent operations were suspended as the UK went into lockdown to free up hospital beds during the first wave of coronavirus - but in May NHS England told hospitals they should restart procedures.
In normal times an announcement of £3bn to help the NHS in England cope with winter pressures might look generous.
But these are not normal times as the government pumps tens of billions into the economy to soften the blows of the coronavirus crisis.
The head of NHS England, Sir Simon Stevens, has been in talks with the Treasury to get guarantees that the Nightingale hospitals can stay open through until next spring in case there is another Covid surge.
He also wanted secure funding in place to do a deal with private hospitals to help tackle the backlog of cancelled non urgent operations such as hip and knee replacements.
That money now seems to have been secured, though we await further details.
The question is, will this be enough to get the health service through what could be one of the most difficult winters in its history?
There have been predictions that the waiting list for routine surgery will swell to 10 million as fears of a second wave of Covid cases in the depths of winter won't go away.
A No 10 spokesman said the funding for England was new and not previously allocated; expenditure will be set out for the devolved nations in due course.
Return to work?
The UK's chief scientific adviser Sir Patrick Vallance told MPs on Thursday there was "absolutely no reason" to change the government's current guidance on working from home.
Since late March the government has advised people to work from home if possible to help curb coronavirus.
But last week Mr Johnson signalled a change, saying: "I think we should now say, well, 'Go back to work if you can'."
Image copyright House of Commons Image caption Sir Patrick wore a mask as he spoke to the Commons Science and Technology Committee on ThursdaySecond wave fears
Earlier this week a report, requested by Sir Patrick, called for immediate action to reduce the risks posed by a second wave of coronavirus this winter.
Among its recommendations were increasing the capacity of the test and trace programme and having more people vaccinated against flu.
Asked to model a "reasonable" worst-case scenario, scientists suggested a range of between 24,500 and 251,000 virus-related deaths in hospitals alone, peaking in January and February.
The estimate does not take into account any lockdowns, treatments or vaccines.
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Research suggests the virus can survive longer in colder conditions and is more likely to spread when people spend more time indoors.
Experts are also concerned the NHS will be under extreme pressure, not just from a resurgence of coronavirus but also from seasonal flu and a backlog of regular, non-coronavirus workload.
No 10 said the increased prevalence of seasonal illnesses was also likely to increase individual's vulnerability to infection, particularly among the elderly.
The potential for a rise in other respiratory viruses with similar symptoms also presents challenges for the capacity of the government's test and trace programme, Downing Street added.
Health Secretary Matt Hancock has already announced plans for the "biggest flu vaccination programme in history", with expanded eligibility criteria expected to be set out shortly.
'We need transparency'
The British Medical Association chairman, Chaand Nagpaul, called for clarity on how the £3b funding will be used.
"The government talks of winter planning, but we need transparency on this, including how far this money can stretch in tackling a modelled worst-case forecast - including a second peak, additional non-Covid demand and a possible flu outbreak," Dr Nagpaul said.
"Crucially, the government must make prevention a priority and take every necessary step to try and avoid a national second spike all together."
NHS Providers, which represents hospitals and other NHS organisations, echoed the call for clarity over what the money will be used for, saying funding is already in place for Nightingale hospitals and private beds.
While welcoming the financial support, deputy chief executive Saffron Cordery added: "Trusts need more than that. They have got to recover the lost ground of the last four or five months and put measures in place to manage the additional activity that always happens in winter."
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