Schools in Scotland and Wales are to close from Friday in response to the coronavirus epidemic.
It is expected the UK government will announce shortly that schools in England will follow suit.
Scotland First Minister Nicola Sturgeon says schools have now lost too many staff to continue as normal.
Meanwhile, the government is bringing forward emergency legislation to protect private renters from eviction after being urged to do more for them.
On Tuesday, Chancellor Rishi Sunak announced £350bn of help for companies and mortgage “holidays” for home owners.
Confirmed coronavirus cases rose in the UK to 2,626 on Wednesday, from 1,950 on Tuesday. A total of 71 people have died.
There have been 56,221 tests carried out in the UK for Covid-19, of which 53,595 were confirmed negative.