Britons are being urged not to undo the success of social distancing over the Easter bank holiday, as Boris Johnson begins his coronavirus recovery.
A publicity campaign tells people to stay home to have a "safe Easter" even as temperatures rise to 26C (79F).
Downing Street said the PM is now out of intensive care and in "extremely good spirits" at St Thomas' Hospital.
Meanwhile, cabinet minister Robert Jenrick has defended his travel moves amid reports he flouted lockdown rules.
The housing secretary is said to have travelled from London to a second home in Herefordshire, and separately visited his parents in neighbouring Shropshire, according to the Daily Mail and the Guardian.
The government has advised against travel to second homes - and urged people to distance themselves from elderly relatives.
Mr Jenrick, the MP for Newark in Nottinghamshire, said he had been in London on ministerial duties and left for what he described as a "family home" in Herefordshire to join his wife and children.
He added that he visited his parents to deliver essentials, including medicines - allowed by the rules.
The number of people to have died in hospital in the UK after testing positive for coronavirus has risen to 7,978, officials announced on Thursday - up 881 on the previous day.
The prime minister was moved out of intensive care on Thursday evening but remains in hospital, Downing Street has said.
He has been receiving treatment for coronavirus at St Thomas' Hospital in London since Sunday.
No 10 said he "he will receive close monitoring during the early phase of his recovery".
Foreign Secretary Dominic Raab - who is standing in for Mr Johnson - has said lockdown restrictions will stay in place until evidence showed the UK had moved beyond the peak of the virus.
He told the government's daily news conference: "After all the efforts everybody has made, after all the sacrifices so many people have made let's not ruin it now.
"Let's not undo the gains we've made, let's not waste the sacrifices so many people have made.
"We mustn't give the coronavirus a second chance to kill more people and to hurt our country."
He acknowledged it was hard for people hoping to go out and be with their families over Easter, but urged restraint.
"Unfortunately right now we just can't do those sorts of things and I am really sorry about that," he said.
Mr Raab was speaking ahead of a bank holiday weekend forecasted to see temperatures as high as 26C in London on Saturday, though cooler weather is expected on Sunday.
Police forces and local authorities said they had already turned away would-be holidaymakers making journeys to popular destinations on Thursday.
Downing Street has said it gave its "full backing" to officers enforcing the lockdown rules.
A number of Easter-themed government adverts will be running in newspapers and on social media urging people to stay at home during the holiday.
A government spokesperson said: "We understand that people will want to spend time with their friends and families this Easter, and we recognise that we are asking the public to make sacrifices in the fight against this disease.
"We are at a crucial moment in preventing further transmission of coronavirus, and so it is vital that we continue following the government's guidance."
In other developments:
- The government's chief scientific adviser Sir Patrick Vallance has suggested less than 10% of people in the UK have had the virus
- For the third week running, people across the UK emerged on to their doorsteps and balconies to take part in a round of national applause for NHS workers
- The Germany military is to deliver 60 ventilators to the UK to help tackle a current shortfall in the medical equipment
- EU finance ministers have agreed a €500bn (£440bn) rescue package for European countries hit hard by the coronavirus pandemic
- The head of the International Monetary Fund (IMF) has warned the coronavirus pandemic will turn global economic growth "sharply negative" this year
- Concerns have been raised by a senior official in the NHS that children with illnesses unrelated to Covid-19 are going to hospital too late and coming to harm as a result
- Universities across the UK have warned some institutions will go bust because of the outbreak
- Online sales of Easter eggs are surging as UK consumers turn to the internet during the lockdown