Daily coronavirus cases in the UK have broken the 50,000 barrier for the first time since July amid calls for restrictions to be reintroduced.
There were 52,009 new cases, the government said on Thursday. There were also 115 deaths within 28 days of a positive test.
The week-on-week increase is 17.9 per cent, but so far Prime Minister Boris Johnson and his government have refused to opt for a return to rules to make people work from home or wear face masks in public.
He said the government is sticking with its winter Covid plan despite the high number of infections.
Covid rates among children in England also edged up to new high with 1,366.8 cases per 100,000 people aged 10 to 19 in the seven days to October 17 – up week on week from 1,134.9.
“We're watching the numbers very carefully every day," the prime minister said.
“The number of infections are high. But we're within the parameters of what the predictions were ... so we're sticking with our plan."
The last time the daily case load topped 50,000, it was July 17, when 54,674 new cases were reported.
Labour leader Sir Keir Starmer told the government to “get a grip” and speed up its booster programme to control the spread of coronavirus.
During a visit to a pharmacy in central London, Mr Starmer said: “The government said that the vaccine would be the security wall against the virus. And now the government is letting that wall crumble.
“We’ve seen those that most need it are not able to get the jab they need, only I think 17 per cent of children have got the vaccine and the booster programme has slowed down so much that at this rate, we’re not going to complete it until spring of next year.
“So the government needs to change, it needs to get a grip, I think it needs to drive those numbers up to at least 500,000 vaccines a day.”
He said ministers could hit this figure if they use community pharmacists, pop-up vaccine centres and mobilise retired health workers.
Dr Chaand Nagpaul, the British Medical Association chairman, said the refusal to introduce supplementary measures – including Covid passports and mask-wearing in crowded public spaces – amounted to "wilful negligence".
Despite the rising numbers, Downing Street said that Plan B would be activated only if it came under "significant pressure".
The prime minister's official spokesman said there were currently 95,000 hospital beds in the NHS, of which 7,000 were occupied by Covid patients, while about 6,000 were free.
A media blitz is planned to encourage people to take up Covid-19 booster jabs.
“An advertising campaign is due to get under way this week," No 10 said. “That consists of broadcast messaging, TV adverts.”
The spokesman said take-up of boosters will be “a central element of the campaign that we are launching”.
Health minister Edward Argar has said the NHS is under sustainable pressure.
Separate figures published by the Office for National Statistics show there have now been 164,000 deaths registered in the UK where Covid-19 was mentioned on the death certificate.
Health Secretary Sajid Javid said on Wednesday that new cases could reach 100,000 a day.
A leading virologist, Dr Chris Smith of the University of Cambridge, said the numbers were already probably close to 100,000, with about half of all cases being asymptomatic.
"We are looking very hard, we're doing more than a million tests a day now, but probably we do have really high levels bordering on that sort of number at the moment."
UK government ministers are coming under mounting pressure to implement the Plan B winter measures to address rising Covid-19 case numbers and a faltering booster vaccine programme.
Concerns have been raised over a sluggish booster shot programme for over-50s and low uptake of vaccines among 12 to 15-year-olds.
The UK's earlier success with its vaccination programme has led to double-vaccinated people's immunity waning.
Prof Andrew Pollard, director of the Oxford Vaccine Group, said a third shot was needed to improve immunity across the country.
Under Mr Johnson’s winter plan announced in September, Plan B would include a return to working from home for many, mandatory mask-wearing in some settings and vaccine certificates required at large indoor gatherings.