The Prime Minister said rates of infection have increased “very much in the last few weeks”, as pressure grows on the Government to do more to tackle the rise.
Northern Ireland and Wales are bracing for lockdowns in the days after Christmas, and a senior emergency medicine doctor said the rest of the UK must do “whatever it takes” to get infections under control.
Speaking during a visit to Greater Manchester Mr Johnson was asked whether England would follow Northern Ireland in imposing stringent restrictions after the festive period.
He said: “We’re hoping very much that we will be able to avoid anything like that. But the reality is that the rates of infection have increased very much in the last few weeks.”
Schools minister Nick Gibb earlier insisted England’s tier system, which will see swathes of southern and eastern England move to the toughest restrictions, is “very effective”.
But he added “we rule nothing out” when asked about the possibility of a national lockdown after Christmas.
The president of the Royal College of Emergency Medicine, Dr Katherine Henderson, described a “real perfect storm” for hospitals as they try to balance increased numbers of Covid-19 patients with non-Covid work and a lack of beds.
She told the PA news agency: “It seems to me we need to do whatever it takes to get the situation firmly under control so that we can vaccinate people and then move forward.”
Dame Donna Kinnair, chief executive and general secretary of the Royal College of Nursing, said nurses would not enjoy Christmas “knowing what awaits them in January”, amid fears of what she predicted could be an “unrelenting tsunami” of cases following relaxed restrictions.
She said ministers should give “fresh and more detailed” advice to the public with a week to go until Christmas.
Dr Nick Scriven, immediate past president of the Society for Acute Medicine, said a period of mixing next week “strikes fear into the hearts of clinicians on the front line”.
New figures from the Office for National Statistics suggest half of adults across the country are planning to form a Christmas bubble.
The survey, carried out between December 10 and 13, before Mr Johnson urged people to scale back their festive plans, also found that fewer people are planning social activities such as meeting in pubs, cafes or bars, compared with last year.
Up to three households are able to mix between December 23 and 27, while travel to and from Northern Ireland is also permitted on December 22 and 28.
It is thanks to our loyal readers that we can continue to provide the trusted news, analysis and insight that matters to you. For unlimited access to our unrivalled local reporting, you can take out a subscription here and help support the work of our dedicated team of reporters.