Hospital admissions are also rising as the latest coronavirus subvariants, Omicron BA. 4 and BA. 5, spread.
A total of 3.5 million people are estimated to have had coronavirus last week, up 29 per cent from 2.7 million the previous week, according to the Office for National Statistics.
“Infections are showing no signs of decreasing, with rates approaching levels last seen in March at the peak of the BA. 2 wave,” said Sarah Crofts, ONS head of analytical for its Covid-19 infection survey.
“Rates have continued to increase across the UK and among all age groups. We will continue to closely monitor the data.”
The number of estimated cases is the highest since April but below the record of 4.9 million infections at the end of March.
So far, Omicron has had five sub-variants that are being monitored closely.
Many countries have registered recent increases in BA. 4 and BA. 5, with the latter becoming the most dominant, according to pathogen surveillance.
With each new wave of Covid-19 variants, populations generally build stronger protection through recent infection, widespread vaccinations, or both.
In its latest Covid-19 emergency committee briefing on Tuesday, the World Health Organisation said reported cases increased by 30 per cent over the past two weeks.
On Friday, the UK’s ONS data showed the virus remained most prevalent in Scotland, where 334,000 people were estimated to have had Covid-19 in the week to July 7, or around one in 16.
In England, 2.9 million people were likely to have had Covid-19 last week, the equivalent of around one in 19.
Wales has seen infections jump to 183,500, or one in 17 people, up from 149,700, or one in 20.
In Northern Ireland, infections have increased to an estimated 107,600 people, or one in 17, and that is the highest level since the beginning of April, and up from 98,400, or one in 19.