The UK’s R number is on the increase again in the latest sign that the country’s coronavirus outbreak is worsening. The latest estimate from Sage puts the crucial figure at between 0.9 and 1.0 – higher than last week when it was between 0.8 and 1.0. It’s the first time in eight weeks that the R – which represents the average number of people each Covid-19 positive person goes on to infect – has ticked upwards. When the figure is above 1, scientists warn an outbreak can grow exponentially.

An R number between 0.9 and 1 means that on average every 10 people infected will infect between 9 and 10 other people. Meanwhile, the R value in England is between 0.8 and 1, but Sage said it is not confident that R is below 1 in all English regions, particularly in London and parts of the South East. It predicts the R in London could be as high as 0.9 to 1.1. The north east and north west – previously the two worst-affected regions – now have an estimated R number of between 0.7 and 0.9. It comes after England’s national lockdown from November 5 to December 2 had seemingly successfully brought down infection rates.

However, these hard-won gains were short-lived and now all signs show the pandemic is steadily picking up speed again. The Government’s daily dashboard shows cases have increased over the last week after falling rapidly during lockdown. Declines in the number of deaths and hospital admissions also appear to be levelling off. The R has been steadily falling from a high of 1.3-1.5 on October 16 to the 0.8-1.0 seen last week and its rise – although small – will concern experts. Sage has also put the latest growth rate of the virus at between -2% and 0%. This means that the number of new infections is shrinking by between 0% and 2% every day. This is again a worse picture than last week when the growth rate was -3% to -1% per day.