Covid-19 infections appear to be slowing in areas of England that were first hit by the new coronavirus variant, although they continue to rise in other regions, according to data released on Friday.

The mixed picture emerged as government scientists said in their weekly bulletin that cases were increasing across the country, while two other well regarded research teams showed overall declines.

However all three studies showed that the trends were more favourable in London, the South East and East of England — the regions where the new and more infectious coronavirus variant first struck.

The government’s official weekly estimates put R — the average number of new cases generated by an infected individual — at between 1.2 and 1.3 for the UK as a whole, equivalent to a growth rate of 2 to 5 per cent per day. The figures come from SPI-M, a committee of Covid-19 modelling experts who report to the government’s scientific group for emergencies, Sage.

However the government statement said: “There are some initial indications that areas that have had higher prevalence levels and been under tougher restrictions for a longer period of time (East of England, London, and South East) are experiencing a slight decline in the numbers of people infected.”

The Zoe Covid study, based on a million weekly reports from people with a symptom-tracking app, found that the R value was 0.9 for the entire UK. Zoe researchers put R at 0.8 in London, compared with 1.2 in north-west England.

The third set of estimates came from a modelling team at Cambridge university’s Medical Research Council Biostatics Unit, who said R was just below one for England as a whole and between 0.46 and 0.80 in London.

Professor Daniela De Angelis, lead author of the MRC study, said: “The combination of the Tier 4 restrictions introduced on December 19 and reduced activity over the Christmas period has resulted in decreased transmission . . . This work implicitly incorporates the impact of the new variant, but its presence makes any projections of how the pandemic will evolve in the near future highly uncertain.”

Professor Tim Spector of King’s College London, lead scientist on the Zoe study, said: “It’s great to see case numbers falling in most regions but numbers are still worryingly high and hospitals will stay under pressure for some time yet . . . We need numbers to keep falling before we make any changes to current restrictions.”

The government scientists put R in London between 0.9 and 1.2, which means that the rate of change in infections in the capital lies somewhere between a decline of 2 per cent per day and growth of 3 per cent a day.

“Regions such as the north west and south west [of England] continue to see infections rise, which is likely to reflect the spread of the new variant in these areas,” the scientists said. In north-west England, R is between 1.2 and 1.5 and the infection growth rate between 3 and 7 per cent a day.

The most closely watched indicator of coronavirus infections, the Office for National Statistics survey, is missing this week because of “delays in receiving laboratory test results”.

“We will publish our latest figures as soon as we can be assured they meet the highest quality,” the ONS said.