A survey by tech company ZOE and King's College London, based on swabs of people with and without symptoms, also suggested the R number could be at 0.8.
And it estimated symptomatic cases had fallen by a quarter since last week.
In a statement, the Department of Health and Social Care said: "There is variation across the country with R estimated to be below one in areas that have been under tighter restrictions for longest.
https://www.bbc.com/news/health-55768033