Britain's National Health Service (NHS) is in danger of being "overwhelmed" by the surge in Omicron cases, Health Secretary Sajid Javid warned on Thursday, despite further evidence it causes less severe illness than earlier Covid-19 strains.
Javid said officials were monitoring the data "hour by hour" after new figures showed the Covid infection rates in Britain reaching record levels with an estimated 1.4 million people with the virus.
The warning came as the UK Health Security Agency (UKHSA) estimated someone with Omicron was between 31 per cent and 45 per cent less likely to have to go to an emergency room and 50 per cent to 70 per cent less likely to be admitted to hospital than an individual with the Delta variant.
The findings are broadly in line with studies published on Wednesday by Imperial College London and the University of Edinburgh.
Javid said that, while the UKHSA conclusions were "promising," Omicron cases were continuing to rise at an "extraordinary rate."
"Hospital admissions are increasing, and we cannot risk the NHS being overwhelmed," he said in a statement.
"This is early-stage analysis and we continue to monitor the data hour by hour.
"It is still too early to determine next steps."
Earlier the health secretary confirmed the government would not be announcing any new restrictions for England before Christmas.
But his comments raise the prospect that ministers are preparing to act as early as next week if the cases continue to grow at a rapid rate.
The devolved administrations in Scotland, Wales and Northern Ireland have all already announced they are putting in place measures once Christmas is out of the way.
NHS national medical director Professor Stephen Powis said the health service was on a "war footing" as the variant continues to sweep through the country.
"We are once again ramping up to deal with the rise in Covid infections," he said.
"Staff are making every possible preparation for the uncertain challenges of Omicron."
NHS Providers chief executive Chris Hopson said hospital trusts were looking to expand capacity to deal with a major influx of new admissions.
"We are identifying places that would be needed if we really, really needed to surge.
"We can do this, but the issue is, we're in incredible pressure right the way across the health system," he told the BBC.
The UKHSA emphasized that its findings regarding the severity of Omicron were "preliminary and highly uncertain" because of the small numbers of confirmed cases currently in hospital.
Ministers were divided over the need for restrictions in the run-up to Christmas, with Javid and Communities Secretary Michael Gove reportedly pressing for action, while Chancellor Rishi Sunak and Foreign Secretary Liz Truss argued more data was needed.
Meanwhile, a slew of new data underlined the pressures facing the NHS.
Covid-19 infection levels in Britain have reached record levels, with 1.4 million people estimated to have had Covid-19 last week, new figures show.
This is the highest number since comparable figures began in Q3 2020, with around one in 45 people in private households in England having Covid-19 in the week to December 16.
This is up from one in 60 the previous week, according to the latest Office for National Statistics (ONS) data which was published on Thursday.
One in 45 is the equivalent of about 1.2 million people, and is the highest number since the ONS began estimating infection levels for England in May 2020.
The percentage of people testing positive for Covid-19 in the latest week is estimated to have increased in all regions of England except the North East, South West and West Midlands, where the trend is uncertain, the ONS said.
In London, around one in 30 people was likely to test positive in the week to December 16 - the highest proportion for any region.
In Wales, around one in 55 people is estimated to have had Covid-19 in the week to December 16, unchanged from the previous week and below the recent record high of one in 40.
In Northern Ireland, the latest estimate is one in 50 people, also unchanged from the previous week and slightly below the record high of one in 40 in mid-August.
For Scotland, the latest estimate is one in 70, up from one in 80 the previous week and below September's peak of one in 45.
Meanwhile, the ZOE Covid study estimates that on average one in 45 people in Britain currently have symptomatic Covid, increasing to one in 43 in England.
According to new analysis, published on Thursday, the ZOE study estimates that half of all people experiencing new cold-like symptoms are likely to have symptomatic Covid-19 and not just a "harmless cold".
This has been calculated by comparing the number of new cases of a cold-like illness to the number of new cases of confirmed Covid-19, it added.
Professor Tim Spector, lead scientist on the ZOE Covid Study app, said that public messaging needed to change "urgently" to acknowledge that for many people Covid-19 symptoms will feel more like a common cold.
He added: "Over the past few days, we saw self-isolation rules already causing havoc for our front line workers, so I'm pleased to see that the government has reduced the isolation period down to seven days.
"However, what continues to shock me is the misinformation in their latest stay-at-home guidance about the symptoms of Covid.
"ZOE data clearly shows that the most important symptoms are no longer a new continuous cough, a high temperature or loss of taste or smell.
"For most people, an Omicron positive case will feel much more like the common cold, starting with a sore throat, runny nose and a headache.
"You only need to ask a friend who has recently tested positive to find this out. We need to change public messaging urgently to save lives as half of people with cold-like symptoms now have Covid."
