Professor Chris Whitty has warned ministers that the Omicron variant of COVID-19 will trigger a “significant increase in hospitalisations”.
England’s chief medical officer also told a virtual cabinet meeting on Tuesday that it is “too early to say how severe” the strain is.
Professor Whitty told ministers he can not yet determine whether cases are plateauing in South Africa, where the strain was first identified, and said there is “no reliable evidence” from the nation’s scientists of a peak in case rates.
“He added that it remained too early to say how severe the Omicron variant was but that we can expect a significant increase in hospitalisations as cases increase,” according to Number 10’s account of the meeting.
Earlier, South African Medical Association chairwoman Dr Angelique Coetzee told MPs on the science and technology committee that most cases of Omicron have been mild.
Prime Minister Boris Johnson warned his ministers that he believes a “huge spike” of cases of the variant will hit the nation.
But Downing Street insist no further coronavirus restrictions are being planned – with the PM urging Britons to get their booster jabs.
The stark messages delivered to the cabinet came as almost 60,000 new COVID-19 cases were reported, the highest total since 9 January, driven by the surge in the highly-transmissible variant.
Health Secretary Sajid Javid told MPs there was a “very real risk” that the exponential rise of Omicron cases could translate into a rise in hospital admissions that “threatens to overwhelm the NHS”.
Mr Javid told MPs that even if Omicron did turn out to be less severe than the Delta variant, the fact it was so easily spread meant “it still has the potential to overwhelm the NHS”.
MPs were voting on the Plan B regulations in the Commons on Tuesday, with the measures expected to pass despite the expectation there will be a revolt on the Tory benches, particularly over COVID passes.