Video report by ITV News Correspondent Libby Wiener
His decisions over how and when restrictions may be lifted will be informed by the latest Covid-19 data, which he, his colleagues and scientists will be examining closely over the weekend.
So, what data will be they be focusing on – and what does it suggest about how well the lockdown in England is working?
The key data falls into six categories:
Rate of new cases of coronavirus
Number of hospital admissions and patients
Success of the vaccine rollout
Level of deaths
Estimated number of infections within the community population
Estimated reproduction number (R), or growth, of the virus
Northern Ireland, Wales and Scotland have all revealed their first tentative steps out of lockdown in the past few days.
Young children in Scotland and Wales will be returning to school next week, but it is expected to be a while before all pupils are back behind their desks.
New cases of Covid-19
The impact of the lockdown can be seen most strikingly in the steep decline since Christmas of the number of new cases of Covid-19.
A total of 74,961 new cases were recorded in England in the seven days to February 14 – the equivalent of 133.2 per 100,000 people.
This is down sharply from a peak of 680.8 cases per 100,000 people on January 4, the day England's lockdown was announced.
It is also the lowest seven-day rate since October 4, when the figure stood at 124.8.
Of the 315 local authority areas in England, only 13 recorded a rise in rates in the seven days to February 14.
The level of rates across England varies considerably, however.
The highest rates are currently in Corby in Northamptonshire with 317.1 per 100,000 followed by Middlesbrough (289.4) and Sandwell in the West Midlands (271.0).
The lowest are all in Devon: Torridge (14.6), West Devon (19.7) and South Hams (21.8).
The regional rates for London, eastern England and south-east England which all saw soaring cases driven by the Kent variant are the lowest they have been since the autumn.
But rates in other regions have dropped only to levels last seen in early to mid-December.
Any blanket lifting of restrictions across England would need to be handled carefully, to avoid fuelling the local and regional differences in case rates.
The number of patients in hospital in England with Covid-19 has fallen sharply in recent weeks.
A total of 15,633 patients were in hospital as of 8am on February 18, according to the latest figures from NHS England.
This is down 54% from a record 34,336 patients exactly one month earlier on January 18.
But while this is a sizeable drop, numbers at both a national and regional level are still higher than when England came out of its second lockdown on December 2.
And while some regions such as the South East and South West have seen numbers decline to their lowest since mid-December, others such as the Midlands and the North West have fallen only to where they were at Christmas.
All regions continue to report patient numbers well above those seen in May 2020, when Boris Johnson announced the initial easing of the first lockdown.
Meanwhile the number of daily hospital admissions of patients with Covid-19 stood at 1,311 on February 16: down 68% from a peak of 4,134 on January 12, but still above the 1,262 on the day England came out of its second lockdown on December 2.
A total of 14,214,176 people in England had received a first dose of Covid-19 vaccine up to the end of February 18, according to NHS England.
This is the equivalent of 24.5% of the total population of England, and 31.2% of people aged 18 and over, based on the latest population estimates from the Office for National Statistics (ONS).
The latest available breakdown for age groups in England is for doses given up to February 14.
By this date, an estimated 93.4% of people aged 80 and over had received their first dose, along with 99.3% of people aged 75-79 and 92.3% of people aged 70-74.
There are wide variations between regions, however.
An estimated 97.9% of people 80 and over in south-west England had received a first jab by February 14, compared with 81.2% in London.
NHS England figures also show that 94.5% of residents of older adult care homes in England eligible to have their first dose of Covid-19 vaccine had received the jab by February 14, as well as 69% of eligible staff in older adult care homes.
Care home residents and staff are classed as eligible for the vaccine if they have not had Covid-19 in the previous 28 days.
NHS England said the number of eligible residents includes a small number of residents at care homes currently undergoing an outbreak and which cannot be visited, who did not receive the vaccine for valid medical reasons, and those for whom consent had not been provided.
Around 88% of patient-facing NHS Trust healthcare workers are likely to have had their first dose of vaccine by February 14, NHS England added.
The current wave of coronavirus deaths peaked on January 19.
A total of 1,280 deaths involving Covid-19 occurred in England on this date, according to the latest figures from the Office for National Statistics.
This is the most comprehensive measure of Covid-19 mortality, as it covers all mentions of Covid-19 on death certificates.
Since January 19, the daily death toll for England has been on a slow and broadly downwards curve, dropping back below 1,000 on January 29.
The latest ONS data runs up to February 5.
More recent figures published by the government, based only on people who have died within 28 days of testing positive for Covid-19, show the daily death toll in England has fallen from a seven-day average of 903 on February 1 to 453 on February 14.
This is the lowest seven-day average since December 22.
Separate figures from NHS England, based on the number of people who have died in hospital who have tested positive for Covid-19, show deaths of people aged 80 and over fell from 475 on the peak day of January 19 to 199 on February 10 – a drop of 58%.
This compares with a fall of 47% among people aged 60 to 79 and 51% for people aged 40 to 59.
All measures of Covid-19 deaths show the numbers heading in a downwards direction, though they remain well above the levels recorded when England came out of its second lockdown on December 2.
Around one in 115 people in private households in England had Covid-19 between February 6 and 12, according to new estimates from the ONS.
This is down from around one in 80 people for the period January 31 to February 6.
It is the lowest figure since the week to December 5, when the estimate also stood at one in 115 people.
The current estimate is the equivalent of around 481,300 people, down from an estimated 1.13 million for the week ending January 9.
These figures refer to the likely number of current Covid-19 infections within private residential households in England.
They exclude hospitals, care homes and other institutional settings.
The estimates suggest that the lockdown has helped drive down the positivity rate, from around 2% of the community population at the start of the year to just under 1%.
By comparison, at the beginning of September 2020 the ONS estimated around one in 1,400 people in England had Covid-19, the equivalent of 39,700 people or 0.07% of the population.
The reproduction number (R) for coronavirus in England was estimated on February 19 to be between 0.6 to 0.9, meaning on average every 10 people infected will infect between seven and nine other people.
The estimate, which has been published by the government and the Scientific Advisory Group for Emergencies (Sage), is slightly lower than the 0.7 to 0.9 it has been in the previous two weeks.
But it is also the same as the very first recorded estimate for the R number in England, on May 29, 2020.
At the start of 2021 the R number for England was estimated as between 1.1 and 1.4, meaning on average every 10 people infected were infecting between 11 and 14 others.
Additional figures published on February 19 suggested the number of new infections is shrinking in England by between 3% and 6% every day.
Once again there are regional variations within the data, with infections estimated to be shrinking by between 1% and 5% each day in north-east England and Yorkshire, and by between 5% and 9% in south-east England.
But the numbers will give further encouragement to Mr Johnson and his colleagues that the lockdown has been a success and may influence the speed and scope of England’s “road map” out of the current restrictions.