Prime Minister Boris Johnson urged Britons to stay home and outlined stricter measures yet to come in the fight against the coronavirus.
“It’s important for me to level with you – we know things will get worse before they get better,” Johnson wrote in a letter issued by Downing Street.
The letter will be delivered to 30 million households this week.
“We are making the right preparations, and the more we all follow the rules, the fewer lives will be lost and the sooner life can return to normal,” he said.
“At this moment of national emergency, I urge you, please, to stay at home, protect the NHS (National Health Service) and save lives,” he added.
Stay-at-home and strict social distancing rules must be obeyed, warned Johnson.
He contracted the coronavirus last week.
“These rules must be observed. So, if people break the rules, the police will issue fines and disperse gatherings,” he added.
The number of deaths from the coronavirus in Britain has risen to more than 1,000 with over 17,000 infections.
Britain delayed imposing social-distancing measures on its population to stem the spread of coronavirus until last week.
Both Johnson and Health Secretary Matt Hancock tested positive for the virus on Friday.
Prince Charles, the heir to the British throne, also tested positive for the virus.
Fifty-five year-old Johnson has mild symptoms including a temperature and a persistent cough.
He is self-isolating and working from home.