The prime minister only speaks for England, with powers on health is devolved to Scotland, Wales and Northern Ireland.
Speaking in a televised address on May 10, Mr Johnson said his plan was "conditional" and that if a second wave emerges or the R number – the rate at which Covid-19 is spread – increases then the “brakes” will be put on the easing of measures.
The PM stressed it is imperative that the country must avoid a second peak which could overwhelm the NHS.
He said he'd been "working to establish new guidance" to help workplaces become “Covid Secure” - further details are expected on Monday.
But how could the lockdown be lifted across various sectors?
Under lockdown, schools and colleges have largely been closed, except for the children of essential workers, and it is thought this could be among the first restrictions to be eased.
Despite resistance from many councils, Mr Johnson has said "it is our intention to go ahead with that as planned on June 1, a week on Monday."
Adding: "We said we would begin with early years’ settings and reception, year one, and year six in primary schools.
"We then intend from June 15 for secondary schools to provide some contact for year 10 and year 12 students to help them to prepare for exams next year, with up to a quarter of these students in at any point."
The PM previously said it is the "ambition" for secondary pupils facing exams next year to get "at least some time with their teachers" before the holidays.
Some of Britain’s largest housebuilders - including Persimmon, Taylor Wimpey and Redrow - reopened building sites in late April and early May.
Under Government guidance, construction has been permitted if in accordance with social distancing rules, but many companies halted work in response to the crisis.
"Anyone who can't work from home, for instance those in construction and manufacturing, should be actively encouraged to go to work," Mr Johnson said.
“And we want it to be safe for you to get to work," he added.
The Home Builders Federation said the restart would be gradual, being dependent on how far supporting suppliers and services, such as building inspectors, mortgage lenders and conveyancers, can also return to work.
Reduced hot-desking, the closure of office lifts and canteens, and putting tape on the floor to mark where people should stand are among measures being advised by the Government for work places reopening.
Guidance published by the Department for Business, Energy and Industrial Strategy (BEIS) says extra cleaning should be introduced in office spaces and the use of protective equipment should be considered where maintaining a distance of two metres between workers is not possible.
They also say continued home working and staggered shifts should also be encouraged.
The proposals are among a list of guidelines in documents drawn up after consultation with executives, trade bodies and unions across the four nations.
Under the guidance, companies will have to draw up a Covid-19 "risk assessments" before allowing staff to return to work - and share these with employees.
The guidance also says social distancing will have to be maintained, whether on the shop floor, in shopping queues, or in communal spaces.
The app would tell users if they have been near to somebody who has tested positive for coronavirus.
"What that will do is tell people completely anonymously, if they happen to be in close enough contact with somebody else who later finds out they have tested positive for coronavirus – and then that will advise you to get tested," Transport Secretary Grant Shapps told ITV News.
At least half the population must use the app if it is to work, he added.
Social distancing restrictions remain in place, however, with people told to maintain the two-metre rule.
Golf clubs, tennis courts and angling are also all allowed to reopen.
Limited social gatherings could be permitted in any further easing, but should be accompanied by extensive testing and contact tracing, one expert has suggested.
Dr Joshua Moon, research fellow in sustainability research methods in the Science Policy Research Unit (SPRU) at the University of Sussex Business School, said the Government could adopt a “slow release valve” approach to the issue.
He explained a phased approach might see certain sections of the population, for example healthy middle-aged people, given more freedoms initially, but he warned this risked the most vulnerable suffering the hardships of lockdown the longest.
Dr Moon said family “clusters” could gradually be permitted to socialise, but could not make long journeys to do so, while most businesses remained shut.
“The idea is that within those groups you can quite easily test, trace and isolate,” he said, adding that it was harder to monitor for people moving around in public.
In his address to the nation on the roadmap out of lockdown, the PM said some of the hospitality industry could reopen from July 1.
Other public places may also reopen provided they are safe and enforce social distancing.
Guidance from the BEIS says workers in customer-facing roles should have plastic screens to help protect them, while some customer services should be stopped completely if social distancing cannot be adhered to.
Sector representative body UKHospitality has focused its energies on getting business support extended to places like bars and restaurants.
A spokesman suggested that even if venues were allowed to open with reduced capacity, businesses would still struggle financially.
Meanwhile pub chain Wetherspoon’s has said it plans to reopen its bars and hotels in June and said that due to it having larger than average pubs social distancing measures could be applied.
When lockdown was imposed on March 23, restaurants, gyms and garden centres shut their doors to customers, with only essential retailers being allowed to remain open.
On May 10 in his address to the nation, Boris Johnson said he hoped to begin a phased reopening of shops by June 1 at the earliest.
More recently, garden centres and estate agents were both given the go-ahead to reopen on May 13.
On May 26, Government unveiled its full list of retailers that can reopen under new guidelines.
Ministers were keen to stress the date could change if reductions in coronavirus infections fail to meet expectations and the experience will be very different.
It is understood Culture Secretary Olive Dowden has been working on a plan for major sports to be played behind closed doors when some social-distancing rules are eased.
Weekly meetings are to be held between the Government, Public Health England and medical officials from sports bodies, with the issue due to be on the table when ministers review current measures next month.
Key questions that need to be tackled include testing requirements, burdens on emergency services and the possible impact on fan behaviour – such as impromptu gatherings outside grounds.
Sporting bodies are understood to be keen to resume full training safely as soon as possible.
Golf clubs, tennis courts and angling were all given the go-ahead to reopen from 13 May, while adhering to social distancing measures.
Road hauliers and medical officials will be exempted, while the common travel area with Ireland will be unaffected.
Meanwhile, the Rail, Maritime and Transport (RMT) union warned there was "zero chance" of ramping up transport services soon, amid speculation of an increase on May 11 or May 18 when a new rail timetable is due.
In April, industry sources said no dates have yet been agreed or announced.
Transport Secretary Grant Shapps said in early May that staggering work times could be a way of making public transport safer.
Hand sanitiser stations, spacing on platforms and one-way systems are also among measures that could be imposed, he added.
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