The reproduction number, or R value, of coronavirus transmission across the UK still remains above 1 and is continuing to rise.

Data released on Friday by the Government Office for Science and the Scientific Advisory Group for Emergencies (Sage) shows the estimate for R for the whole of the UK is between 1.2 and 1.5.

Last week, the R number was between 1.1 to 1.4. All regions of England have an R that is higher than 1, according the government’s scientific advisers.

R represents the average number of people each Covid-19 positive person goes on to infect. When the figure is above 1, an outbreak can grow exponentially.

Figures from the Office for National Statistics (ONS) published today suggested in England there were 9,600 cases per day in the week until 19 September – an increase on the the 6,000 a day the previous week.

It comes as London was placed on the government’s watchlist of areas of concern. It means stricter restrictions could be imposed in the capital if cases continue to rise.

Today it was also shown that no local area in England is considered a low risk coronavirus zone within the nation’s new contact tracing app.

The NHS Covid-19 app was rolled out across England and Wales on Thursday after months of delay, designed to automatically alert people of anyone who tests positive that they have been close to.

One element within the app is a localised risk level based on the first part of a person’s postcode.

But in the current environment it is not considered appropriate for anywhere in England to be deemed “low” risk, the Department for Health and Social Care (DHSC) said.