Boris Johnson is set to tell the country on Monday that it is too risky to proceed with lifting Covid restrictions on June 21.
The Prime Minister is considering a delay to reopening of up to four weeks after a surge in cases of the Indian variant.
Britain on Friday recorded the highest number of cases since February 26 and infections have risen 58.1 per cent week on week.
A four-week delay could now pushing the reopening date back to July 19.
Masks and social distancing are set to continue – and there is to be no green light for larger weddings.
But on Saturday night a senior minister said there were fears the planned delay would leave a "very short window to open up", with further postponements leading to an eventual re-opening in the spring, when transmission occurs less easily and winter strains on the NHS have eased.
Here is everything we know.
Why is there a delay?
The Prime Minister has faced growing pressure to push ahead with the reopening on June 21, despite cases of the Indian variant doubling every 4.5 days in some areas of England.
The news of the delay came as cases appear to have trebled in the past week in the UK, from 12,431 to 42,323, since the introduction of the new variant.
A further extension to the restrictions currently in place would see businesses such as nightclubs remain closed.
Nearly six million people are being urged to minimise travel, as Matt Hancock insists the “goal” remains for the country to leave lockdown together.
Military personnel and extra testing have been deployed to stop the spread of the Indian variant.
The Indian variant is increasing across the country
However, hospitals in Covid hotspots are seeing a "significantly" lower death rate among people admitted for treatment and are coping with current levels of infection, the head of NHS Providers said on June 9.
Chris Hopson, chief executive of the body which represents NHS trusts, said there was a degree of confidence that vaccines have "broken" the link between infections and the "very high level of hospitalisations and mortality we’ve seen in previous waves".
Is the UK on track to hit vaccination targets?
Hopes for a full reopening on that date have also been affected partly by the news that both the Pfizer and AstraZeneca jabs give only 33 per cent protection after one dose, compared with up to 80 per cent protection against previous variants.
Almost 78 per cent of UK adults have had one jab, but only around 55 per cent have had two.
It now seems that the ministers believe the delay will give the Government time to get more people vaccinated.
There is now a race to offer all over-50s a second coronavirus vaccine dose.
Step-by-step unlocking: what happens when?
The roadmap is underpinned by four key tests that are linked to data, which act like a checklist that must be met before moving on to the next step of reopening.
The tests determine whether the vaccine roll-out is going as planned; vaccines are effective in bringing down deaths and hospitalisations; case numbers are not rising so fast that the NHS risks being overwhelmed; and new variants do not create unforeseen risks.
The British Medical Association became the latest body to call for a delay after data released on Friday, June 11, showed the ‘R’ rate at its highest since January – between 1.2 and 1.4 – with daily cases reaching 8,125, the highest number since February.
Figures published by Public Health England showed that 42,323 cases of the Indian variant have been confirmed in the UK – an increase of 240 per cent from last week. PHE estimates that the strain is 60 per cent more transmissible than the Kent or alpha variant, with cases doubling every four and a half days in some parts of England.
Below are the changes of the roadmap since May 17 and those that were expected on June 21, before the delay.
Roadmap – May 17
Since May 17, groups of up to six people and two households can meet indoors, meaning that people can now enter each other’s homes.
Hugging is allowed between close family and friends, who can choose whether or not to socially distance. However, people are being "urged to remain cautious", and wider social distancing rules remain for adult social care, medical, retail, hospitality and business settings.
Pubs and restaurants can open indoors and venues are allowed to serve food and drink, but hospitality guidance must be observed, such as individuals remaining seated. There are no requirements for guests to be socially distanced at tables during this stage.
The rule of six and two households rule was also introduced indoors from this date. It has been lifted outdoors, meaning people can meet in groups of up to 30 in beer gardens or when dining al fresco.
Care home visiting has been eased further, with residents able to have up to five named visitors and greater freedoms to make low risk visits outside of the establishments.
University students can return to face-to-face teaching on campus, replacing online lectures that have been in place for months. They should get tested twice a week upon return.
Funerals are no longer be limited to 30 mourners. Instead, the capacity is determined by how many people could be accommodated in venues such as places of worship or funeral homes while maintaining social distancing.
However, the cap of 30 people remains for weddings and other types of significant events, including bar mitzvahs and christenings.
Up to 30 people can attend a support group or parent and child group. The limit does not include children under five.
Hotels and B&Bs can open, meaning small group trips are back on the cards, with up to six people or two households able to meet indoors.
Additionally, professional performances can now resume indoors. There is no official guidance on the number of performers permitted, but this is determined based on the capacity of the venue.
Indoor sports and gym classes can also open, along with entertainment venues, including cinemas and theatres. New rules are in place for different sizes of venues.
People took part in a gym class starting one minute past midnight amid an easing of coronavirus restrictions, at the Park Road Fusion Lifestyle Gym in London on May 17
Credit: Neil Hall/EPA-EPE
Normal outdoor events can open for up to 4,000 people or 50 per cent of the venue capacity, whichever is smaller. Similarly, normal indoor events can open for up to 1,000 people or 50 per cent capacity, again whichever is lower.
For huge outdoor seated venues, there is a special limit. Up to 10,000 attendees are allowed or 25 per cent capacity, whichever is lower. This means, for example, Wembley Stadium can open with 10,000 fans in attendance.
The ban on overseas holidays ended on May 17, in the first step to reviving foreign travel. It is no longer illegal to go abroad, meaning summer holidays overseas are now allowed, with a traffic light system for countries in use.
However, The Telegraph reported on June 7 that Mr Hancock warned Britons that summer holidays abroad are off for the "medium term" because of the need to protect domestic freedoms "at all costs".
However, Downing Street declined to rule out the possibility that Mr Johnson could go on an overseas holiday this summer on the same day George Eustice, the Environment Secretary, suggested people should be taking their summer holidays in the UK.
Mr Eustice told Sky News on June 8 he would be holidaying in Cornwall this year, adding: "Our advice has been don’t travel unless it’s absolutely necessary.
On June 3, ministers added Portugal, including the islands of Madeira and the Azores, to the amber list after tests revealed what are believed to be previously unknown variants of Covid.
It means that anyone returning from the tourist hotspot to the UK will have to quarantine for 10 days and take at least two PCR tests.
Read more: What to do about your holiday to Portugal as country moves from green to amber list
No countries will be added to the green list, dashing frontrunner Malta’s hopes of opening its holiday market to Britons. Hopes that the Balearics or Greek islands could be added have also been scuppered.
Traffic light travel restrictions
Instead, seven countries have been added to the red list, forcing anyone returning from them to quarantine in government-approved hotels at a cost of up to £1,750 per person.
Egypt, Sri Lanka, Costa Rica, Bahrain, Sudan, Trinidad and Tobago and Afghanistan have been added to the red list.
But, in their first ever face-to-face meeting, Mr Johnson and US President Joe Biden will announce a new joint travel task force in a concerted effort to see the return of transatlantic tourism.
The Telegraph understands the task force will report back with recommendations next month, offering the hope of US holidays later this summer being salvaged.
Could there be another lockdown in 2021?
The low death rate in recent weeks led Mr Johnson to state that "nothing in the data" suggests that a third national lockdown will be implemented but local lockdowns have not been ruled out.
However, communities Secretary Robert Jenrick said on June 9 that there were no plans to return to last year’s regional tiered approach to coronavirus restrictions, adding that the "best way forward" is replicating the targeted action in Bolton.
He told BBC Radio 4’s Today programme: "We don’t have any plan to return to the regional or the tiered approach that we saw last autumn.
"What we want to do is provide as much support as we possibly can to a local community and to work as closely as we can with the local leaders."
Fears are growing that lockdown laws could be replaced with a web of restrictive guidance in what has been dubbed by critics a “smoke and mirrors” reopening.
On June 8, official guidance urging people in Covid hotspots to meet outside if possible and minimise travel was extended to Greater Manchester and Lancashire.
Roughly 10 per cent of the population of England is now being advised to restrict travel out of the affected areas.
The measures are already in place in Bolton, Blackburn with Darwen and other hotspot areas and were on June 8 credited by the Health Secretary with stemming the rise in cases.
Despite this, scientists said the variant had “radiated” into neighbouring boroughs.
The areas where the Indian variant is increasingly prevalent
In response to the spread of the Indian variant, which has been blamed for the recent spike in cases, the Government wants to vaccinate as many as one million people a day as part of a drive to save the British summer.
Mr Hancock said the package of measures in Bolton and other areas had “seen a capping out of the increase in rate without a local lockdown, thanks to the enthusiasm of people locally and of course the vaccination programme”.
He told MPs on June 8: “That is our goal. Our goal is that England moves together, and that’s what we are putting these programmes in place to do, and we are seeing them work.”
The additional measures include surge testing, contact tracing, isolation support and efforts to maximise vaccine uptake.
Read more: The hotspots for the Indian variant of Covid-19 in the UK