One in 15 people had Covid in England last week, new data suggests.
Researchers from the Office for National Statistics (ONS) said that around 3.2 million people in England alone are thought to have the virus in the seven days to December 31.
In Wales and Scotland the figure is thought to be one in 20, while one in 25 people are thought to have had Covid in Northern Ireland.
But the First Minister of Scotland warned the numbers are expected to be higher than the one in 20 shown and will continue to get worse.
Nicola Sturgeon told MSPs: "The results of the most recent ONS survey, published just a few minutes ago, suggest that in the week to December 31 that had risen to one in 20."
A total of 15 hospitals have declared 'critical incidents' amid mounting staff absences caused by Covid.
Morecambe Bay NHS Trust, Blackpool Teaching Hospitals NHS Foundation Trust, The United Lincolnshire Hospitals NHS Trust, the Great Western Hospitals NHS Foundation Trust, University Hospitals Plymouth NHS Trust and University Hospitals Dorset are among the hospital trusts that have signalled they may be unable to deliver vital care to patients due to staff shortages.
Meanwhile, 17 hospitals in Greater Manchester have paused non-urgent surgery and appointments, although a critical incident has not yet been declared at the sites.
The news comes as follow-up PCR tests will be axed throughout the UK for people who get Covid with no symptoms.
The UK Health Security Agency has agreed a change in policy for millions of people who test positive for the virus by lateral flow.
The change will take effect from January 11 in England, and from tomorrow in Wales and Scotland. Northern Ireland's rules will similarly change.
Currently, anyone who tests positive using a lateral flow test (LFT) has to get a follow-up PCR test to confirm their result.
After the rule change, people who test positive with no symptoms - said to account for around 40% of people with Covid - will no longer need this follow-up PCR test.
They will still have to isolate for at least seven days, but only from the date of their positive lateral flow test.
The change - last performed in January-March 2021 - will effectively cut the isolation time because it takes a couple of days to get and await the result of a PCR test. This could ease crippling staff shortages including in the NHS.
It will also ease the demand for PCR tests after people struggled to get appointments in the Omicron wave.
People with Covid symptoms will still be told to get a PCR test, regardless of their lateral flow result.
The change was confirmed for England. Wales, Scotland and Northern Ireland would announce any changes in their testing regime separately.
