The UK currently has the highest Covid-19 death toll in Europe and the fifth-largest in the world.
To offset an increasingly battered economy, the British government has been borrowing record amounts in emergency money.
But new Covid-19 cases are rising by at least 6,000 per day in Britain, according to week-old data, hospital admissions are doubling every eight days, and the testing system is buckling.
"The trend in the UK is heading in the wrong direction and we are at a critical point in the pandemic," Chris Whitty, the government's chief medical officer, will say at a briefing at 1000 GMT on Monday.
"We are looking at the data to see how to manage the spread of the virus ahead of a very challenging winter period," Whitty will say alongside Patrick Vallance, the chief scientific adviser.
Transport Secretary Grant Shapps said the United Kingdom was at a critical juncture though any new lockdown would have to be balanced with schools and businesses allowed to stay open so that the country could pay for the crisis.
"We're certainly at a very critical moment this morning," Shapps told Sky. "It is clear that we are just a few weeks behind what we're seeing elsewhere in Europe."