NHS doctor have shared their fears the coronavirus pandemic will force them to ration access to ventilators and hospital beds if resources fall short.
Hospitals across the UK are now striving to at least quadruple the number of intensive care beds to meet an expected surge in serious virus cases, senior physicians told Reuters.
One doctor said patients may have to be prioritised in order of survivability if the pressure on life-saving hospital resources worsens in coming weeks.
And another warned people at highest risk of dying from the illness need to have some tough conversations with their families about their wishes.
It comes as the UK death toll hit 177 today with 39 more deaths in England in the last 24 hours.
The government announced a drastic expansion of lockdown measures across the UK today, shutting pubs, clubs, restaurants, theatres and gyms in a bid to reduce the spread of the virus.
The busy medical professionals fighting the Covid-19 horror expressed dismay preparations had not begun weeks earlier.
With serious shortages of ventilators, protective equipment and trained workers, the physicians said senior staff at hospitals were beginning to confront an excruciating debate on intensive care rationing.
However they said Britain may be a long way from potentially having to make such horrific decisions.
Rahuldeb Sarkar, a consultant physician in respiratory medicine and critical care in Kent, said local NHS trusts across the country were reviewing decision-making procedures drawn up, but never needed, during the 2009 swine flu pandemic.
The procedures cover how to choose who, in the event of a shortage, would be put on a ventilator and for how long.
Decisions would always be based on an individual basis if it got to that point, taking into account the chance of survival, he said.
But nevertheless, there would be difficult choices.
"It will be tough, and that's why it's important that you know, that two or more consultants will make the decisions."
Sarkar said the choices extended not only to who was given access to a ventilator but how long to continue if there was no sign of recovery.
"In normal days, that patient would be given some more days to see which way it goes," he added.
But if the worst predictions about the spread of the virus proved correct, he suspected "it will happen quicker than before".
Britain is by no means the only country that faces having its health system overwhelmed by COVID-19, but the data on critical care beds - a crucial resource in the fight against the disease - is concerning for UK authorities.
Estimates of the potential death toll in Britain range from a government estimate of around 20,000 to an upper end of more than 250,000 predicted by researchers at Imperial College.
NHS England said it was crucial to reduce the coronavirus's infection rate to ease peak pressure on the health system.
"Unmitigated, there is no health service in the world that would be able to cope if the virus let rip," said NHS England head Simon Stevens.
"In the meantime, what the NHS is doing, of course, is pulling out all the stops to make sure that we have as many staff, beds and other facilities available."
Health Secretary Matt Hancock said on Sunday that hospitals had around 5,000 life-saving ventilators but that they needed "many times more than that".
The physicians interviewed by Reuters said, if ventilators were secured, the aim was to increase intensive care beds from around 4,200 to over 16,000, partly by using beds in other parts of hospitals.
Rob Harwood, a consultant anaesthetist in Norfolk who has worked in the health service for almost four decades, said access to critical care could ultimately have to be determined by patient scoring systems for survivability.
Systems developed for SARS, another type of coronavirus that broke out in 2003, could for example be refined, he added.
"Once you have exhausted your capacity and exhausted your ability to expand your capacity you probably have to make other decisions about admission into intensive care."
But he emphasised that, for now, admission criteria would
stay unaltered: "We are a country mile from that at the moment."
The coronavirus has also exposed how generally ill-equipped the health system is for a pandemic.
The British Medical Association said doctors have been asked to go to hardware stores and building sites to source protective masks.
Some doctors are worried about Public Health England's (PHE) new advice last week which reduces the level of the protective equipment they need to wear.
Previously, staff on ward visits were told to wear full protective equipment, comprising high quality FFP3 face masks, visors, surgical gowns and two pairs of gloves.
But the new advice recommends only a lower-quality standard paper surgical face mask, short gloves and a plastic apron.
PHE referred queries about doctors' worries to the health department, which did not respond to requests for comment on the matter.
A senior NHS epidemiologist, who was not permitted to be named, told Reuters this advice was based on a sensible assessment of the biohazard risk of the virus. "It's not Ebola," the doctor said, pointing out the risk to medical staff without
underlying medical conditions was low.
Matt Mayer, head of the local medical committee covering an area in south of England, said GPs had been sent face masks in boxes that said "best before 2016" and that have been relabelled with new stickers reading "2021".
The department of health said that they had tested certain products to see if it is possible to extend their use.
"The products that pass these stringent tests are subject to relabelling with a new shelf-life as appropriate and can continue to be used," a spokesman said.
Dr Alison Pittard, dean of the Faculty of Intensive Medicine and a consultant in Leeds, northern England, said there had been chronic under-investment in critical care in Britain.
But she said the country was not yet at the stage where it had to make calls about rationing patient resources.
She said, if rationing became necessary, medical ethics should still prevail and guidelines needed to be issued on a national level so that no patient was worse off based on where they lived.
The NHS might need also need the advice of military leaders, she said, on how to effectively triage - meaning prioritising which patients are seen and treated first based on their level of need.
Stephen Powis, the National Medical Director of NHS England, said there were plans to issue new guidance to give doctors advice on how to make difficult decisions if there was a surge in coronavirus cases, like in Italy.
Dr Pittard said patients with pre-existing conditions who already had life-threatening health difficulties should be having conversations with their family about how they wished to spend their last days, in the event of them being infected.
She said at-risk patients should be considering: "If I get coronavirus now I've got a very high chance of dying of it.
"So do I want to die in hospital and when my relatives can't come in to visit me because it's too risky, or would I like to die at home?
"And if I do want to go into hospital, do I then want to go to intensive care where my chances of surviving are minimal?"
