Britain said it was taking the unprecedented step of helping to pay workers' wages in an attempt to prevent a surge in unemployment as companies grapple with the near shutdown of the economy due to the coronavirus outbreak.
"Today I can announce that for the first time in our history the government is going to step in and pay people's wages," finance minister Rishi Sunak said.
He said there would be no financial limit to the size of the plan.
Moments earlier, Prime Minister Boris Johnson ordered the closure of pubs, restaurants, gyms, nightclubs and other businesses for Friday as it ramped up the country's attempts to slow the spread of the virus.
Sunak said the government would give grants to cover 80% of a worker's salary if businesses kept them on staff.
"The economic intervention that I am announcing today is unprecedented in the history of the British state," he said.
Other measures announced by Sunak included an extra 7 billion pounds for the welfare system.