Swathes of southern England are said to be teetering on the strictest Tier 3 coronavirus restrictions.
The COVID Sympton Study app has predicted which Tier 2 areas are most at risk of being upgraded, when the government reviews the current tier allocations this week.
Essex, Thurrock and Southend on Sea, London, Somerset and Bath and North East Somerset, Gloucestershire, and Wiltshire and Swindon were the areas predicted to be most at risk of Tier 3, The Sun reports.
Meanwhile, Bristol, South Gloucestershire and North Somerset were among the areas predicted by the app to move down a tier, from 3 to 2.
This is based on key data points including the case rate per 100,000 people, and the concentration of cases in the over-60s.
The app, which is a collaboration between ZOE and King’s College London, launched a new platform earlier this month called the English Tier Dashboard.
This uses data from the people who have downloaded the app, as well as from publicly available sources.
Researchers track areas based on alignment with five key indicators, which the government will consider before deciding which areas should belong in which tiers.
These five indicators are: case numbers across all age groups, cases among the over-60s, the change in R rate, the percentage of population with coronavirus, and pressures on the local NHS.
Tim Spector, the app's principal investigator, said he believes the majority of the country should be placed in "some form of tier 2 until Easter, to keep mobility down and make it harder for virus to spread".
In a tweet yesterday (Sunday), he explained: "Stop-start restrictions appear to be failing and actually fuel the virus.
"Give people more local information about their local NHS and schools."
The government is due to announce the revised tier allocations on Wednesday (December 16).
These are expected to last until the next review two weeks later, except for the five-day relaxing of the rules over Christmas.
In a report sent to the government today (Monday, December 14), the researchers shared a regional breakdown of the seven-day prevalence rates of coronavirus, per 100,000 of the population.
Only these areas were listed in the report as seeing a rise in their prevalence compared to the previous week: Cornwall and the Isles of Scilly, East and West Sussex and Brighton and Hove, and London.
