Night clubs, theatres, gyms, cinemas and leisure centers must also close on the same timescale, said Johnson during his daily briefing in Downing Street.
Co-chairing the press conference with Johnson, Chancellor of the Exchequer Rishi Sunak outlined the government's highly expected new package to protect workers and their employers from the novel coronavirus.
Describing the economic intervention as "unprecedented", the chancellor announced that the government will step in and help pay wages to protect jobs for the first time in British history in the "coronavirus job retention scheme".
The government will cover 80 percent of wages for employees who are unable to work due to coronavirus, up to 2,500 pounds (about 2,910 U.S. dollars) a month, Sunak added.
"Today I can announce that for the first time in our history the government is going to step in and pay people's wages," he said.
"Let me speak directly to businesses: I know it's incredibly difficult out there - we in government are doing everything we can to support you,"said Sunak, adding that "The government is doing its best to stand behind you and I'm asking you to do your best to stand behind our workers."
Responding to the new measures, Carolyn Fairbairn, director general of the Confederation of British Industry (CBI), said on Twitter, "This is a landmark package for business, people and jobs. Rishi Sunak's offer of payroll support and fast access to cash will support livelihoods of millions."
"Today marks start of UK fightback - enterprise & government, people & unions working together," tweeted Fairbairn.
Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders, said "The Chancellor's unprecedented package of emergency funding and tax support will come as a huge relief to automotive companies of all shapes and sizes as they battle to safeguard their businesses and support thousands of workers and their families who otherwise face hardship."
"Ninety-nine percent of UK automotive output is now halted meaning thousands of businesses are counting their future, not in months or weeks, but in days," said Hawes, adding that "We need these measures implemented swiftly and will work closely with government and our members to keep this critical and fundamentally competitive sector alive."
Catherine McGuinness, policy chair at City of London Corporation, tweeted: "Today's strong unprecedented measures by Rishi Sunak will help cushion the economic impact of COVID-19 for businesses and workers alike."
"In particular, the deferral of VAT for Q2 and move to pay 80 percent of wages for employees not working will help struggling businesses retain staff," McGuinness added.
As of 9 a.m. local time (0900 GMT) Friday, the number of confirmed COVID-19 cases in Britain reached 3,983, according to UK's Department of Health and Social Care. As of 1 p.m. (1300 GMT), 177 patients who tested positive for coronavirus have died. (1 pound = 1.16 U.S. dollars)