There are routinely more than 50,000 new cases being recorded each day as an aggressive new strain of the virus takes hold.
Health workers are stretched to the limit, and among them are many Australian professionals.
Here, three Australian nurses tell first-hand of their experiences.
I'm in one of the best, most safely staffed hospitals in the UK, but even we no longer have enough doctors, nurses or beds. On my past three shifts we've been between three and six nurses down.
In Accident and Emergency (A&E) we're seeing 300 to 350 patients a day. That's about the same as during the first wave, but their acuity has increased, meaning they are sicker and need greater care.
We've also got lots of people turning up with non-emergencies because they can't see their GP.
In April, we had extra doctors redeployed from other areas and a special COVID intubation team. Hypoxic patients could be instantly intubated and in ITU (intensive care) within 30 minutes if necessary. The efficiency was amazing.
But now we have limited extra support because other health services like outpatient clinics and non-emergency surgeries are still running.
We're also accepting ICU transfers from hospitals that have no capacity. It's great we can offer that support, but soon we'll have to stop because we won't have capacity ourselves.
At one point last night, we had eight ambulances waiting outside to deliver patients, and a wait time of about 1.5 hours.
The anxiety when you're walking into a shift is huge. We know it's going to be hard, but just how hard is the question.
There have been times when I felt like I wasn't able to give my patients the care they needed, or I'd not advocated well enough for them. I've just been scrambling all day, not taking toilet breaks — or not even needing a toilet break because I haven't even had time to drink enough water.
That's the hardest part: feeling like you've not given someone the care they deserve.
Luckily, I've stayed healthy so far. I've been on the Oxford vaccine trial since June, so I've been swabbing weekly for that, as well as doing COVID sensitivity tests twice a week.
Emily Regan (centre), pictured with family during a holiday in Cornwall, says she has seen burnt-out nurses leave the industry.(Supplied)
I am lucky to have good mental health, but it's been hard to see colleagues struggling. I have seen some brilliant nurses just be done with it all and leave. It is such a loss.
On Boxing Day, morale was really low. We were just so busy and understaffed, and I found myself becoming easily irritated. My colleagues noticed I wasn't my usual upbeat, joking self. I try to put on a friendly, happy face for my patients but it can be draining, so my colleagues aren't getting the best version of me when they need it the most.
Occasionally, I run into COVID deniers protesting outside the hospital. It no longer shocks me. I just don't engage. I originally did but there's no point anymore. People don't want to have an educated discussion.
Once someone's seen a patient who is hypoxic from this virus and is aware of the time and resources directed at saving their life, then they have the right to an opinion. Otherwise, stay in your lane. I'm not going to waste my limited time on you.
Seeing everyone at home lead normal lives is difficult at times, but I've lived in the UK for four years now and built a life here.
As hard as this past year has been, I love my job and have incredible friendships with my colleagues. I don't want to walk away from all of that.
But we're burnt out, and it's made harder by the necessary restrictions. We can't socialise and blow off steam outside work like we used to. We can't visit friends and have them make us a cup of tea and just look after us for a little while.
About 60 per cent of the staff in my department are from overseas, so many of us don't have families here either. We're all just really tired. Things are terrible and we know it's only the start of the next wave.
Louise Faint fears more people will die if the nation's hospitals become overwhelmed.(Supplied)
I work in A&E in one of the UK's worst-hit areas.
It's pretty much as close to the COVID front line as you can get and the situation is deteriorating.
A few weeks ago we could go a few hours without seeing any patients in the "hot" area, where COVID cases are treated, and now we're seeing 10 or more every shift.
It doesn't sound like many, but most of those are quite poorly and require lots of care and close monitoring. And like everywhere, we are short staffed.
If hospitals are overwhelmed there's a greater chance people will die unnecessarily simply because we won't be unable to provide the care they deserve.
Louise Faint says she has battled loneliness and burnout.(Supplied)
I've been a nurse for a little under three years but I only joined A&E last January.
In this past year, I've experienced my first CPR, my first resuscitation attempt and my first patient deaths.
Last week, I had two patient deaths over two shifts. One was somewhat expected but the other was a normally fit and well 30-year-old who was brought in in cardiac arrest.
Seeing their families is usually what upsets me the most. Their cries and distress are haunting.
It's been heartbreaking to see very sick patients go through it all alone because visitors weren't allowed.
I've held the hands of lonely, elderly people while they fought for breath. I've tried to reassure families about their loved ones over the phone when I wasn't even sure myself.
Louise Faint says having her boyfriend Alex (right) with her in England has helped her.(Supplied)
I've battled loneliness too. The pandemic began not long after I moved over, and then the national lockdown was announced and my boyfriend's move from Perth was delayed.
I was working seven days a week just so I could be with other people and not alone with my thoughts. It was a really low time. I was stressed, bordering on the edge of depression, and I made myself sick from overworking. In May, my boyfriend arrived and things got better.
Now, though, a lot of staff are totally burnt out. We have short fuses and get worked up over small things that would normally not be an issue, such as doctors requesting another x-ray after we've already taken the patient for one.
I struggle to sleep before my shifts and I've stopped seeing the good in my day-to-day life. I never feel like I'm rested or have had a break. On my days off I barely have the energy to move off the sofa.
Louise faint, pictured in PPE, says staff struggle to keep up with changing coronavirus policies.(Supplied)
The way the UK Government has handled things has caused a lot of confusion. The tier system is terrible and restrictions change so suddenly that making plans is next to impossible.
Even for medical staff, the rules change a lot. There are constant updates to policies and regulations surrounding PPE, swabbing, results timeframes, admission criteria, and trying to determine what's potential COVID-19 and what's asthma.
Staff often feel like they are out of the loop and being put at risk.
But I have a stable job and I have learnt so much.
I came to the UK because I couldn't get a job as a newly qualified nurse in Western Australia. I went to an NHS nursing expo in Perth in March 2019 and was offered one on the spot.
Living overseas has always been a dream of mine and I knew that if I didn't take the leap of faith then I never would.
I'd love to go back and see my family soon but with flights costing at least 3,000 pounds ($5,303) it's not going to happen in the foreseeable future.
Sarah says members of the public "don't seem to understand, or care, how dangerous COVID is".(Rawpixel: Chanikarn Thongsupa)
At the start of the year, when it became clear we were facing a pandemic, I was retrained to work in intensive care.
My background is in respiratory nursing but I had never worked a day in an intensive care unit (ICU) before, not even in university rotations.
I was petrified, but it was essential.
Intensive care shifts are 10 times more stressful than other shifts.
Patients are so sick, and COVID patients deteriorate so much faster. A normal shift might have one deterioration a day. A COVID ICU shift will have multiple patients deteriorating and multiple patients dying.
Normally, one nurse will look after one or two patients on breathing machines in an open space. That is the safe ratio. During COVID the ratio is more like one to four or five, and now they are all in single rooms, making them effectively invisible if they deteriorate.
My first ICU shift was in the middle of the night. I was meant to be doing a "shadow shift" — following a nurse around to get an introduction — but we had no staff, so as the most senior of the learning nurses I was asked to take a patient.
During the shift my patient deteriorated and could no longer tolerate the breathing machine.
They were intubated at 5:00am. It was a tricky intubation with a lot of different medical professionals involved. I had to quickly learn about new medications, a new breathing machine and complicated new settings. I have never been more stressed in my life.
Sadly, the patient passed away. I went home that morning and just cried.
The numbers now are higher than they were in April. That is terrifying.
People don't seem to understand, or care, how dangerous COVID is. They aren't taking it seriously anymore, or they think they are invincible.
I have one friend who thinks it's made up. I can't even bring myself to argue with them now because I get too angry.
The hardest thing has been pretending to loved ones in Australia that I'm fine when really I've been very scared and homesick.
I've nearly gone home on multiple occasions, but I stay because I feel I have a duty to the NHS and to the sick people of the UK.
Some days it's almost impossible to be strong for my patients. I've cried with husbands and wives, sons and daughters on the telephone. I try to put them at ease when deep down I don't whether the person they love will survive or not.
It scares me that my own family are so far away and I have no way of getting home to them quickly. But I love my hospital and I'm so proud to be part of the NHS. None of this is their fault.
*Not her real name.
Kate Guest is an Australian journalist based in the UK
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