People shielding against coronavirus can now leave their home and return to work, as a further easing of lockdown restrictions in England is postponed.
More than two million at high risk will no longer need to isolate in most of England, Scotland and Northern Ireland.
It comes after the PM applied the brakes to easing restrictions further and as some businesses remain closed.
England's chief medical officer warned the UK may have reached the limit on lifting lockdown as cases rise.
Prof Chris Whitty said the "idea that we can open up everything and keep the virus under control" is wrong.
Asked whether it was safe for England's schools to fully reopen to all pupils in the autumn, Prof Whitty said it was a "difficult balancing act" but "we have probably reached near the limit, or the limits, of what we can do in terms of opening up society".
Meanwhile, a new report suggests more than half of the people furloughed during the pandemic are now back at work, as companies begin contributing to the costs.
When lockdown began in March, those considered extremely clinically vulnerable - an estimated 2.2 million people in England - were advised to stay at home, or shield, to avoid contracting Covid-19.
People in high-risk categories include those who have had an organ transplant, are receiving immunosuppression drugs, undergoing chemotherapy and radiotherapy, or have severe respiratory conditions.
Now, they can return to work if they cannot work from home and as long as their workplace is Covid-secure. It is still advised they maintain social distancing when outside.
From Saturday, those who were shielding in England, Scotland and Northern Ireland will no longer receive food boxes and medicine deliveries from the government.
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But shielding advice remains in place for Blackburn with Darwen in the north-west of England, Leicester and Luton, and the most vulnerable will continue to shield in Wales for another two weeks.
Boris Johnson on Friday announced that the further easing of lockdown restrictions in England - due to come in this weekend - would be postponed for at least a fortnight.
It means that the following will not be able to take place until 15 August, at the earliest:
the reopening of casinos, bowling alleys, skating rinks and remaining close contact services indoor performances pilots of larger gatherings in sports venues and conference centres the expansion of wedding receptions to allow up to 30 people beauty treatments that involve the face, such as eyelash, eyebrow and threading treatmentsThe rethink on easing England's lockdown follows new restrictions for people in parts of northern England, after a spike in virus cases.
New lockdown rules were introduced in areas including Greater Manchester, east Lancashire, and parts of West Yorkshire. The rules include a ban on separate households meeting each other inside their homes and private gardens.
Face coverings will be mandatory in more indoor settings, such as cinemas, with the new rules being enforceable in law from 8 August.
Figures published by the Office for National Statistics (ONS) on Friday suggest infection rates in England are rising, with around 4,200 new infections a day - compared with 3,200 a week ago. However, the level of infection is still significantly lower than it was during the peak of the pandemic.
A further 120 people have died with Covid-19 in the UK according to the latest DHSC figures, bringing the total number of virus deaths to 46,119. Meanwhile, 880 new lab-confirmed cases have been recorded - the highest in more than a month.
Are you getting married this weekend? Or were you reopening your business? How will the postponement affect you? Share your experiences by emailing haveyoursay@bbc.co.uk.
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