Downing Street said the Prime Minister experienced mild symptoms on Thursday and was then tested.
Everyone has to stay at home and will only be allowed to leave for reasons like shopping for basic necessities or for exercise.
Boris Johnson said he is 'absolutely confident we can send coronavirus packing in this country'.
The PM has been urged to announce a 'financial package for people' to support them through the coronavirus outbreak.
If anyone in a household develops symptoms, everyone who lives there should stay at home for 14 days.
Boris Johnson called the Covid-19 outbreak 'the worst public health crisis for a generation'.
Experts have warned Boris Johnson after he repeatedly suggested a crossing over the Irish Sea.
Speaking to a Holyrood committee, he said tunnelling would be cheaper than the bridge suggested by Boris Johnson.
The First Minister has told the PM that the £20bn would be better spent in Scotland and Northern Ireland.
Boris Johnson accused of 'personal animosity' towards Nicola Sturgeon as he hints at blocking FM's attendance.
Britain officially split from the European Union at 11pm, three-and-a-half years since the Brexit vote.
After 11pm, Britain will immediately enter a transition arrangement with the EU, keeping it aligned with Brussels.
The First Minister said a ballot could be held without Westminster's consent provided it's ruled as legal.
More than half of Scots would vote for independence - but they don't support a referendum this year.
Immigration is reserved to Westminster but the Scottish Government is calling for powers to be split.
Some MPs cheered as royal assent was confirmed for the European Union (Withdrawal Agreement) Act.
The Welsh Assembly joined Holyrood and Stormont in formally refusing consent to the Bill.
The First Minister's spokesman said she remains 'committed' to holding a vote this year.
MSPs were told by the UK Government medicine pricing would not be part of post-Brexit negotiations.
The Prime Minister said a new independence vote would cause continued 'political stagnation'.