The reproduction number, or R value, of coronavirus transmission across the UK has risen above 1.
Data released on Friday by the Government Office for Science and the Scientific Advisory Group for Emergencies (Sage) shows the estimate for R across the UK is between 1.0 and 1.2.
It comes after the Government announced a ban on social gatherings with more than six people from Monday while all of Merseyside was added to the local lockdown watchlist amid a surge in cases.
The growth rate of coronavirus transmission, which reflects how quickly the number of infections is changing day by day, has increased slightly.
For the whole of the UK, the latest growth rate is between minus 1 per cent and plus 3 per cent per day, a slight change from between minus 1 per cent and plus 2 per cent last week.
The growth rate means the number of new infections is somewhere between shrinking by 1 per cent and growing by 3 per cent every day.
The ONS said in recent weeks there has been an increase in the number of people testing positive for Covid-19 aged 17 to 24 years and 25 to 34 years.
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But they said the number of people testing positive for Covid-19 aged 50 years and over appears to be stable or declining.
Katherine Kent, co-head of analysis for the Covid-19 Infection Survey, said: “Our results this week suggest that there has been an increase in Covid-19 infections in England during recent weeks with higher infection rates among 17-34-year-olds.
“These findings highlight how important it is that we continue to monitor Covid-19 infections in the country.
“We are grateful to our many participants who are continuing to make this survey possible.”
The survey has also begun in Northern Ireland and the ONS said estimates for there will be published when there is a sufficiently large sample.
Work is also under way to set up the survey in Scotland.
Meanwhile. evidence suggests the rate of new infections in private households in England has increased in recent weeks, the ONS said.
An average of 3,200 people per day were estimated to be newly infected with Covid-19 between August 30 and September 5, the ONS said.
This is up from an average of 2,000 people per day between August 19 and 25.
