Britain's government will pay a massive share of private sector wage bills to discourage bosses from firing staff as it resorts to war-time levels of borrowing to prop up the economy during its coronavirus shutdown.

"Today I can announce that for the first time in our history the government is going to step in and help to pay people's wages," finance minister Rishi Sunak said on Friday.

There was no limit on the size of the plan which the government will fund by selling more debt, as it will for other measures worth tens of billions of pounds rushed out over the past 10 days.

Sunak also allowed businesses to hold on to 30 billion pounds ($35 billion) of value-added tax (VAT), which they would normally pass on to tax authorities.

Moments earlier, Prime Minister Boris Johnson ordered the closure of pubs, restaurants, gyms and other businesses from Friday to slow the spread of the virus.

The centrepiece of Britain's coronavirus crisis plan is a new grant covering 80% of workers' salaries - up to a maximum of 2,500 pounds ($2,930) a month each - if firms kept them on.

"The truth is we are already seeing job losses and there may be more to come," Sunak said. "I cannot promise you that no one will face hardship in the weeks ahead."

The package of measures rushed out by the government this month could push Britain's budget deficit back to 10% of gross domestic product, its peak after the global financial crisis, JP Morgan economist Allan Monks said.

Meanwhile, Ireland's government yesterday said it was also considering plans to pay up to 75% of the wages of thousands of staff temporarily laid off as a result of the coronavirus pandemic, the Irish Times reported.