Boris Johnson has placed the UK on lockdown to tackle the coronavirus, with a ban on public gatherings of more than two people, to be enforced by police.

The prime minister detailed a short list of reasons why individuals may leave their homes as he ordered the immediate closure of all shops selling non-essentials items.

“We will stop all gatherings of more than two people in public – excluding people you live with,” he said.

“And we’ll stop all social events​, including weddings, baptisms and other ceremonies, but excluding funerals.”

In an unprecedented televised address to the nation, Mr Johnson set out the only reasons people may leave their homes, which are: for one form of exercise a day; shopping for essentials; travelling to and from essential work, and for medical needs.

“That’s all – these are the only reasons you should leave your home,” he said.

“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.

“If you don’t follow the rules the police will have the powers to enforce them, including through fines and dispersing gatherings.”

Shopping for basic necessities should be as infrequent as possible, and the exercise may be alone or with members of the same household, he said.

Anyone who is not following the rules could be fined, and police will have powers to disperse gatherings.

Although parks will remain open for exercise, gatherings will be dispersed.

To ensure compliance with the instruction stay at home, Mr Johnson said all shops selling non-essential goods, including clothing and electronic stores, would be closed.

Libraries, playgrounds, outdoor gyms and places of worship will also be shut, the prime minister announced.

Mr Johnson assured the public that the restrictions are to be kept under constant review, and they could be relaxed in three weeks if evidence shows the government is able to do so.

He said that “no prime minister wants to enact measures like this,” adding: ”To put it simply, if too many people become seriously unwell at one time, the NHS will be unable to handle it – meaning more people are likely to die, not just from coronavirus but from other illnesses as well.”