Coronavirus cases are “getting out of control” in parts of the UK as ministers consider shielding hundreds of thousands of vulnerable people.
Skills minister Gillian Keegan said the country faced an “unbelievably serious situation”.
The warning comes as Health Secretary Matt Hancock said he is “very worried” about a surge in hospital admissions and is pressing for tougher restrictions to be imposed in the north of England.
Yesterday, it was revealed the government is expected to sign off on a three-tier system of lockdown restrictions next week.
Under the new system, pubs and restaurants could be closed in the worst-hit areas, while a ban on overnight stays is also being considered.
Ms Keegan told BBC's Question Time: "This is serious - it is getting out of control, and we have to do something to bring it back under control."
One such measure could include a plan to tell hundreds of thousands of at-risk people to stay at home over winter in infection hotspots.
Doctors are warning the NHS faces an "implosion" of hospital admissions if drastic measures are not taken now, The Times reported.
However, a decision on shielding has not been taken after ministers raised concerns that telling people to spend months at home alone could have adverse mental health effects.
Meanwhile, in another sign of tension at the top of government, Chancellor Rishi Sunak is reportedly resisting the “traffic light” system of lockdown.
Mr Sunak is said to be furious over a plan to shut down the hospitality sector as part of the simplified system, with Mr Hancock and his health department accused of trying to “bounce” Boris Johnson into the move.
It comes after the British economy grew by a paltry 2.1 per cent in August - scuppering hopes of a "V-shaped recovery".
"Today's figures show our economy has grown for four consecutive months, but I know that many people are worried about the coming winter months," Mr Sunak said of the disappointing statistics.
Asked about reports of the traffic light system, business minister Nadhim Zahawi told Sky News "the best thing to do is wait for decisions" but admitted that government leaks were "confusing" and "corrosive".
Writing in the Daily Telegraph today, Labour leader Sir Kier Starmer said the government had "lost control of the virus" and urged ministers to "get a grip".
He wrote: “It was an act of gross irresponsibility for anonymous No 10 sources to tell a few newspapers on Thursday about plans to impose further restrictions on millions of people, without any detail, without any consultation and without any statement from the prime minister.
"This has significantly added to the sense of confusion, chaos and unfairness in the approach that is being taken."