The UK's R number has fallen to between 0.9 and 1, according to new figures.
Scientists have estimated the reproduction number, known as the R number, is now edging below one. R represents the average number of people each COVID positive person goes on to infect.
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It comes as the daily infection rate dropped slightly, with the UK recording a further 16,022 coronavirus cases and 521 related deaths.
On Thursday 17,555 cases were recorded along with 498 deaths.
According to the Government Office for Science and the Scientific Advisory Group for Emergencies (SAGE), the latest R number means every 10 people infected with coronavirus will go on to infect between 9 and 10 people.
The growth rate estimate for the UK has also shrunk by 2% to between -2% and 0%, meaning the number of new infections is shrinking by between 0% and 2% every day.
A breakdown of R numbers across England
England: 0.9 - 1.0
East of England: 0.9 - 1.1
London: 1.0 - 1.1
Midlands: 0.9 - 1.1
North East and Yorkshire: 0.8 - 1.0
North West: 0.7 - 0.9
South East: 1.0 - 1.2
South West: 0.9 - 1.1
When the figure is above 1, the COVID-19 epidemic will continue to grow but if it is below 1, it shows the outbreak is in retreat.
Last week, the R number was said to be between 1 and 1.1.
These latest estimates are based on the data available up to 24 November.
The Government Office for Science said the impact of England's lockdown, which started on 5 November, is only beginning to be observed in the R number this week.
However, scientists said R estimates for England may continue to fall and may already be below 1 for all regions.
SAGE has also said that a divergence in policies across the four nations that constitute the UK mean "the estimate of R for the entire UK has become less meaningful in recent weeks".
According to a government adviser, the government's new Tier 3 and Tier 2 interventions, which are due to come into effect on 2 December, should keep the R number below 1 in the run up to Christmas.
But areas in Tier 1 may continue to see a growth in coronavirus infections.
It comes as new figures from the Office for National Statistics (ONS) on Thursday showed there were an estimated 633,000 people in private households in England with COVID-19 between 15 and 21 November - a slight decrease from 664,700 the week before.
When it comes to age groups - only secondary school age children are seeing a rise in infection rates, while they have dropped in adults aged 35 and over, according to ONS figures.
Analysis: The R number could go up again over Christmas
By Ashish Joshi, health correspondent
The epidemic is on the decrease with the R value across the UK and in England probably somewhere between 0.9 and 1.0. The interventions has had its desired effect.
In the North West, North East and parts of Yorkshire we see an R value somewhere between 0.7 and 0.9.
That's good news as these were the regions that were really hit hard by the virus a few weeks ago.
If we look more closely at the data we can see Tier 1 really didn't do much in terms of slowing the spread of coronavirus to any significant degree.
It held in some of these places, but overall it was still growing.
However, Tier 3 did what it was supposed to do. And you can see that in the slowing of the national infection rate.
But the R number, as we have seen, can go up very quickly. That is the worry as we head into Christmas with relaxed measures.
The festive season is seen as a spreader event. If people end up spending a lot of time mixing with others the R number will go up again.
