UK to 'stay alert' as it takes steps toward gradual reopening

Johnson announced a limited easing of restrictions, including allowing people to exercise outside more often and encouraging those who cannot work from home to return to their jobs.

"You must obey the rules on social distancing, and to enforce those rules, we will increase the fines on the small minority who break them," Johnson said.

He detailed an alert system ranging from level 1, where virus is no longer present, to level 5, the most critical, that will allow the government to flag risks in different parts of England and to decrease or increase restrictions where necessary.

Changes will be closely monitored at a local, regional and national level and the government would "not hesitate to put on the brakes" if there are outbreaks, he said.