The summer Covid surge is an early warning for even bigger wave when schools go back in the Autumn, experts fear.
Scientists behind the ZOE Covid study app estimate Covid cases have passed 275,000 a day and could reach 300,000 early next week.
It comes as UK hospitals have recorded around a three-fold increase in Covid admissions in the last month.
Daily symptomatic infections have risen by 142% this month, rising from 114,030 on 1 June to 275,706 on Sunday, according to data based on reports to the Zoe app.
The current spike, which experts believe could peak in the next fortnight, is being fuelled by more infectious Omicron sub-variants BA.4 and BA.5.
They suspect the subvariants may return with a vengeance after the summer school holidays and when the cooling weather leads to more indoor mixing.
Prof Lawrence Young, a virologist at Warwick University, told the i: “This significant rise in symptomatic infections is really worrying and demonstrates that there’s no room for complacency as far as Covid is concerned.
“This wave provides a warning for what we could experience over the autumn and winter.
We need to prepare now for the autumn and winter months when colder weather will drive people indoors increasing the risk of infection.”
More than 1,400 people are now being admitted to hospital daily who test positive for Covid-19. This is up from a low of 460 on May 28.
The R value in England is between 1.1 and 1.4.
The Zoe study suggests infections are now at the highest level they have been for all but three weeks of the pandemic.
Tim Spector, the King’s College London professor who runs the Zoe app, said: “On the current trajectory we will be just under 300,000 cases this weekend. Beyond that I’m not sure if it will plateau or keep rising.”
Symptomatic infections are just the tip of the iceberg as many more cases go undetected because they are symptomless.
Random swab testing by the Office for National Statistics suggests UK cases have nearly doubled in a fortnight to 1.7 million in the UK.
The UK total is 76% higher than at the start of June.
Hospital bosses have warned they may have to cancel some planned operations if the rise continues.
