UK goes into three-week lockdown to tackle coronavirus spread

In a televised address to the nation on Monday evening, he said while no prime minister wants to make such demands on the population, the situation was such that he was forced to clamp down on people's movement and crackdown on any gatherings of more than two people.

With his central message calling on people to restrict their movements outside their homes only for the very basic essentials, Johnson said, "From this evening I must give the British people a very simple instruction – you must stay at home."

People will only be allowed to leave their home to shop for basic necessities, as infrequently as possible; one form of exercise a day – for example a run, walk, or cycle – alone or with members of household; any medical need, to provide care or to help a vulnerable person; and travelling to and from work, but only where this is absolutely necessary and cannot be done from home.

"You should not be meeting friends. If your friends ask you to meet, you should say 'No'. You should not be meeting family members who do not live in your home," the prime minister said.

He said, "You should not be going shopping except for essentials like food and medicine -- and you should do this as little as you can. And use food delivery services where you can."

The UK prime minister warned that anyone flouting these strict rules would have to deal with police, who will have the powers to enforce them, including through fines and force dispersal gatherings.

"No prime minister wants to enact measures like this... But, at present there are just no easy options. The way ahead is hard, and it is still true that many lives will sadly be lost," Johnson said.

"We will beat the coronavirus and we will beat it together. And therefore I urge you at this moment of national emergency to stay at home, protect our NHS (National Health Service) and save lives," he added.

Johnson has indicated the strict curbs on movement would remain in place for at least three weeks, but will be kept under constant review.