Over two million vulnerable people shielding from coronavirus will be able to leave their homes for the first time in months on Monday, despite top scientists warning the Government could be moving too fast.
Primary schools in England will also start to open for Reception, Year 1 and Year 6 pupils tomorrow.
And non-vulnerable groups of up to six people can now meet outdoors, with social distancing.
News of the easing of some restrictions came as people flocked to beaches and parks yesterday in defiance of the lockdown rules that remained in force over the weekend.
Beauty spots were jammed with crowds as temperatures soared, hitting 25C at Heathrow.
The relaxing of the rules for the elderly and vulnerable comes a month earlier than planned.
Official Government advice had initially told those at risk to shield till the end of June.
And the changes come despite the UK threat level remaining at four out of five on the official scale, and Prime Minister Boris Johnson previously suggesting that measures would not be lifted till we hit level three.
But Foreign Secretary Dominic Raab insisted yesterday that the UK is “transitioning” down to level three.
Mr Raab admitted it was a “sensitive moment”, but added: “We can’t just stay in lockdown forever”.
At the No10 briefing on Sunday, Cabinet minister Robert Jenrick said he was “reasonably confident” that the infection rate would remain under control.
Under tomorrow's changes, people considered extremely vulnerable will be able to go outside with members of their household, while maintaining social distancing.
Those who live alone can meet one person from another household outdoors.
For the wider public, larger outdoor gatherings of six people are now permitted, and outdoor retailers and car showrooms are able to reopen from today.
But several of the Government’s own scientific advisers have warned that lifting rules could lead to a second peak.
Prof Peter Openshaw, of the SAGE advisory committee, said: “Unlocking too fast carries a great risk that all the good work that has been put in to try to reduce transmission may be lost. We need to proceed with great, great care.”
Prof Openshaw claimed that there was near unanimity in the scientific community that the Government was lifting restrictions too quickly.
Prof Devi Sridhar, chair of global public health at Edinburgh University, thinks it is “inevitable” that the infection rate will rise.
England’s Deputy Chief Medical Officer Dr Jenny Harries, who backs the changes, said: “This is a really, really critical time. The public really, really need to stick to those measures.”
Charities supporting vulnerable people are also worried about lifting the restrictions. Phil Anderson, of the MS Society, said people “rightly want to hear a lot more about the scientific evidence showing this will be safe for them”, saying the decision has “come out of the blue”.
Gemma Peters, of Blood Cancer UK, said: “The way it was announced with no warning or consultation with charities and clinicians has created confusion and this adds to the impression already created that the shielding group isn’t high enough on its list of priorities.”
Meanwhile, Britain has exceeded its target to increase coronavirus testing capacity to 200,000 a day by the end of May, including 40,000 antibody tests.
Health Secretary Matt Hancock described it as “an important milestone”, although only around 115,000 tests were actually carried out.
A letter sent by 26 senior UK academics and health experts to Downing Street on Sunday said they are “very concerned for the safety and wellbeing of the general public” as the lockdown rules are relaxed.
They warned that the lack of an effective test, trace and isolate system will make it difficult to find and quarantine newly infected people. The scheme will not be fully operational till the end of the month, while the accompanying NHS app is delayed by several weeks.
Government scientist Prof Peter Horby warned at the weekend: “We are entering a period where there is a risk of increasing transmission, but we don’t yet have that safety net fully in place.”
SAGE member Sir Jeremy Farrar, said the track and trace system needs to be “fully working” before measures are eased, warning the virus is still spreading “too fast to lift lockdown in England”.
Another SAGE member, Prof Calum Semple, said a “brave” political decision had been taken on schools, but warned that high levels of transmission were still being seen.