The Prime Minister has decided to ban gatherings of more than two people in public as part of sweeping measures to fight the coronavirus.
In an unusual address to the nation Boris Johnson told citizens of the range of restrictions.
He also outlawed social events, weddings and baptisms – though funerals can still go ahead.
Groups of more than two were banned, unless they are members of your own household.
Announcing the move from No10, Boris Johnson admitted: “No Prime Minister wants to enact measures like this.
“I know the damage that this disruption is doing and will do to people’s lives, to their businesses and to their jobs.”
He added: “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.”
The Prime Minister spent days resisting mounting demands to trigger a Covid-19 shutdown.
But pictures of “selfish” tourists packing sunshine spots and accusations people could not be trusted to follow official advice fuelled the decision, which came at a meeting of the Government's COBRA emergency committee.
Finally bowing to pressure, Mr Johnson brought down Britain's shutters in a primetime television address to the nation.
The PM's speech came less than three hours after Britons travelling abroad were told to return home immediately.
Foreign Secretary Dominic Raab said: “We are strongly urging UK travellers overseas to return home now, where and while there are still commercial routes to do so.
“Around the world, more airlines are suspending flights and more airports are closing, some without any notice.
“Where commercial routes don’t exist, our staff are working round the clock to give advice and support to UK nationals. If you are on holiday abroad the time to come home is now while you still can.”
The UK's coronavirus death toll climbed to 335, with another 46 deaths in England, four in Wales and four in Scotland.
The disease could kill up to 70,000 people unless lockdown measures are beefed-up, research suggests.
Experts at University College London and Cambridge University estimate current measures will result in between 35,000 and 70,000 excess deaths.
Millions of children were at home after schools stayed closed after the weekend – piling extra pressure on stressed families.
