A further 218,724 coronavirus cases and 48 COVID-related deaths have been recorded in the UK, official figures show.
The UK-wide figures have been released after the Bank Holiday, when only England released figures for both deaths and cases.
It comes as a further 141,825 people had their booster jab – bringing the total to 34,363,986, the latest figures show.
A further 19,158 people had a first dose, bringing the total to 51,820,652. Another 29,295 people had a second dose – bringing the total to 47,482,789.
The latest NHS England figures show 14,210 patients with Covid-19 were in hospital on January 3, including 777 requiring mechanical ventilation.
The figures have been released as multiple hospitals declared critical incidents, with nurses calling for more restrictions “without delay”.
In a letter to Health Secretary Sajid Javid, the Royal College of Nursing (RCN) said the NHS could “ill afford” the current level of absences as it called for a “more cautious approach” to COVID restrictions in England.
Prime Minister Boris Johnson is set to lead a Downing Street press conference at 5pm as Number 10 admitted that the health service is facing a “difficult time” during a “challenging winter”.
However, Mr Javid has said there is nothing in the data that suggests England needs to move beyond the current Plan B restrictions.
“I think Plan B, implementing that, has been the right approach and also being absolutely focused on the vaccination programme,” he told reporters during a visit to a vaccination centre in south London.
Officials in Whitehall are keeping an “extremely close eye” on hospital capacity, with admissions and occupancy “increasing significantly”, Downing Street said.
But the prime minister’s official spokesman said: “We’re not seeing that same jump in beds requiring ventilation, which is pleasing, and almost certainly a function of both the nature of Omicron and our successful booster programme.”
He added that the vaccinations and “evidence that Omicron may be milder” means “we are not seeing those huge waves in cases translate into those needing the most serious care that we saw perhaps in previous waves, but that still puts the NHS under significant pressure”.