Boris Johnson is facing mounting calls to delay the final easing of restrictions on June 21 amid fears over the spread of the Delta variant.
The new strain - formerly known as the Indian variant - in now the dominant one in the UK and some scientists have urged caution on taking the last step on the roadmap.
Professor Ravi Gupta, a member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), warned there were signs the country was entering a third wave and called for a delay to allow more people to get both jabs.
But Tory MPs are demanding the Prime Minister presses ahead with easing lockdown, pointing to the success of the vaccine rollout and data showing the UK recorded no Covid deaths on Tuesday - for the first time since July 2020.
Mr Johnson said on Wednesday that there is still "nothing in the data at the moment that means we cannot go ahead with Step 4" but added: "We've got to be so cautious".
The PM is waiting for critical data on the transmissibility of the new variant before he makes his decision, which is expected on June 14.
However in Scotland, Nicola Sturgeon has announced she is pausing plans to ease restrictions in large parts of the country.
The move has ramped up pressure on the PM to slam on the brakes over lockdown.
It wouldn't be the first time England has followed Scotland's lead during the pandemic.
Here are some examples of how announcements north of the border put pressure on the Government in Westminster.
Ban on mass gatherings
Nicola Sturgeon announced she would outlaw gatherings of more than 500 people on March 12 2020, as the virus began to take hold.
The First Minister said the move was focused on easing pressure on the emergency services, as big events would divert police and paramedics away from dealing with Covid-19.
Boris Johnson initially resisted the idea, saying: "The scientific advice, as we’ve said over the last couple of weeks, is that banning such events will have little effect on the spread.”
But a day later, the Government bowed to pressure as bodies like the Premier League and Buckingham Palace began to cancel events.
Big events including the Cheltenham Festival and the Liverpool vs Atletico Madrid Champions League football match went ahead in the days before the ban - which later drew criticism.
School closures
Ms Sturgeon announced that schools would be shut in Scotland on March 18, as she said too many staff were off work with the virus.
The move came into force two days later, with a similar decision taken in Wales.
Education Secretary Gavin Williamson announced hours later that schools would also be closed to most pupils in England.
A-Levels and GCSEs were also cancelled for the summer.
Masks in shops
Shoppers in Scotland were ordered to don face coverings from July 10 last year.
Nicola Sturgeon announced the plans as restrictions began to ease following the first national lockdown.
Ministers in Westminster spent days putting out conflicting statements about the policy before finally agreeing to bring in similar rules late on July 13.
The ban in England didn't come into force until July 24 - more than a week after it was announced by the Prime Minister.
A-Level chaos
Not strictly a lockdown restriction, but another example of where Westminster followed Holyrood came over the exams chaos in 2020.
Exams were scrapped due to prolonged school closures so pupils were due to get their grades based on a mix of teacher assessment and their school's past performance.
However results day in Scotland descended into chaos as tens of thousands of pupils had their marks downgraded on August 4.
The Scottish Government came under sustained criticism over the row before u-turning days later.
In England, a similar row took place when students got their A-Levels on August 13, with tens of thousands of pupils downgraded by the computer algorithm.
After days of anger, the Government performed a major u-turn and said students could use their teacher-assessed grades.
January lockdown
Nicola Sturgeon pipped Boris Johnson to the post by announcing a fresh lockdown first on January 4.
The First Minister revealed Scotland would go into lockdown hours before announcement was made in London, causing irritation in Westminster.
Scotland's lockdown began after midnight on January 5, while England's shutdown began in name on January 4 but MPs had to vote in the changes on January 6.
