Boris Johnson has given the all-clear for schools in England to begin reopening from Monday.
Schools, colleges and nurseries closed more than nine weeks ago due to the Covid-19 outbreak, remaining open only for vulnerable youngsters and the children of key workers.
But from Monday schools will begin resuming with Reception and Years 1 and 6, despite safety concerns from teaching unions.
The Prime Minister announced that England had met the five tests which will allow an easing of the lockdown including the reopening of some shops and letting people meet in parks in groups of six.
People can also now meet in gardens as well as in the park.
He told the daily Downing Street press conference: "I cannot and will not throw away all the gains we've made together and so the changes we're making are limited and cautious.
"It's thanks to the caution you've shown so far that all five met are being met.
"The result is that we can move forward with adjusting the lockdown in England on Monday."
Prime Minister Boris Johnson set out at the daily Downing Street press conference how his five tests for easing the lockdown had been met.
He said the "heroic efforts" of NHS workers and the public mean that the first test of protecting the NHS's ability to cope has been met, with 475 admissions in Covid-19 in England on May 26.
A "sustained and consistent fall in the daily death rate" has been witnessed, meaning the second test has been met, he said.
The Government is satisfied the third test has been met because the rate of infection is "decreasing to manageable levels across the board" with an average of 2,312 new cases being confirmed in the last seven days, he said.
Test four has been met by signing new contracts for protective equipment and boosting testing capacity to 161,214 a day, he said.
On the final test, the PM said that the adjustments have been crafted to not risk a second peak that would overwhelm the NHS.
"This package has been carefully designed so we can ease the burdens of the lockdown while expecting to keep that R below one," he said.
A number of local authorities have advised schools not to open to more pupils from next Monday, citing fears of contributing towards a second coronavirus peak.
A group of experts calling themselves the Independent Sage Group warned reopening schools risks pushing the 'R' rate above one.
Dr Mary Bousted, Joint General Secretary of the National Education Union, said: “Government should be bound to protect all of us during this frightening and difficult time. Yet the announcement today about England pressing ahead with wider school opening flies in the face of this duty. We are not saying only go back when it is 100% safe. Nothing ever is. But we are saying meet your own tests, produce sound scientific evidence, and return when the time is right to ensure the virus can be contained as much as possible.
“Heads, teachers, support staff and school staff have all been working through this challenging time. Schools have been open and contact has been maintained with families and the children they teach. They have done so to support vulnerable children and children of key workers while their parents and carers keep the country going. This has been done bravely and willingly.
“School staff have many questions which should be answered. Why, when the rest of the country is still required to observe social distancing, is it safe for schools not to? Fifteen pupils to a class makes social distancing an impossibility in our small classrooms and in particular with very young children who will not understand the concept. Denmark, who the Government quite rightly praise for their approach to wider school opening has a limit of five children when outside and three when inside.
She added: “Today’s final report from Independent SAGE again casts grave doubt over the Prime Minister’s decision to press ahead with a June 1 wider opening of schools. Independent SAGE said ‘this decision threatens not just the health of school communities but also of wider society’. We fail to understand why the Government would take such risks.
“Time and again we have had to ask for the scientific thinking behind wider school opening. Time and again we have not had the answers.
"The Government's Covid-19 strategy has drifted steadily from dither to disaster. Revelations in recent days have severely damaged public trust, and it is not only troubling but deeply insulting and dangerous to see schools being used as a distraction."
Meanwhile more than two in five teachers say there are not enough sinks in schools for children to regularly wash their hands, a survey suggests.
Health and safety issues facing schools in England will grow if heads are asked to admit more pupils as part of a wider reopening from next week, the National Education Union (NEU) has warned.
Already more than a quarter (26%) of teachers are concerned that pupil numbers are too large to allow social distancing when moving around their school - and a similar proportion (25%) say hand sanitiser is not available in all classrooms and at entrance and exit points, according to a poll by the NEU.
