The UK has reported more than 100,000 daily cases for the first time since of the start of the pandemic.
Some 106,122 cases have been recorded in the latest 24-hour period – around 13,000 more than the previous high of 93,045 on 17 December.
A further 140 coronavirus-related deaths have also been recorded.
The figures compare with 90,629 cases and 172 fatalities reported yesterday.
Last Wednesday 78,610 cases were reported – at the time the highest since the start of the coronavirus pandemic, and a number which the chief executive of NHS England said should “worry us all” – along with 165 deaths.
According to the latest data, 813 COVID-19 patients were admitted to hospital on 18 December.
There are currently more than 8,000 people in hospital – with 849 people on ventilators, the most recent figures show.
On Wednesday Welsh First Minister Mark Drakeford announced new measures to limit the spread of Omicron – as he criticised Prime Minister Boris Johnson’s government for being in a state of “paralysis” and “simply unable to act”.
Government scientists are set to conclude the Omicron strain is milder than Delta for most people, according to reports.
However, the UK Health Security Agency (UKHSA) has not yet confirmed this and is set to announce its latest analysis on the coronavirus strain tomorrow.
Scientists still believe the variant is of “serious concern” amid fears its increased transmissibility could “potentially overwhelm” the NHS.
A UKHSA spokesperson said: “We are reviewing all analyses continuously to help inform the pandemic response, which includes assessing the severity of Omicron.
“We will publish these latest findings in the variant technical briefing on 23 December.”
More than 30.8 million booster and third doses have now been delivered in the UK – with 6.1 million in the past week.
A record 968,665 booster and third doses of COVID-19 vaccine were administered in the UK on Tuesday, new figures show.
The previous record was 940,606 doses on Saturday, according to figures published by the UK’s four main health agencies.
Advisors on the Joint Committee on Vaccination and Immunisation (JCVI) have now recommended vulnerable children aged between five and 11 should be offered a new paediatric version of the Pfizer/BioNTech vaccine – with around 330,000 said to be eligible.
It comes as new research from University College London (UCL) suggested children can fight COVID-19 better than adults due to their innate immune response.