Boris Johnson set out his plans for the staged reopening of shops in England at his Downing Street press conference.

The Prime Minister said: "We will set out our formal assessment of the five tests that we set for adjusting the lockdown later this week as part of the three-weekly review we are legally required to undertake by Thursday.

"But because of the progress we are making I can, with confidence, put the British people on notice of the changes we intend to introduce as we move to step two."

From June 1, outdoor markets and car showrooms will be allowed to open, provided they can do so safely.

He said: "We know that the transmission of the virus is lower outdoors and that it is easier to follow Covid secure guidelines in open spaces."

From June 15, "all other non-essential retail" will be allowed to reopen, contingent on progress in the fight against coronavirus and if the businesses are "covid secure".

The Prime Minister said new guidance was being published for the retail sector "detailing the measures they should take to meet the necessary social distancing and hygiene standards".

"Shops now have the time to implement this guidance before they reopen," he said.

"This will ensure there can be no doubt about what steps they should take."

Boris Johnson said the authorities would "have the powers we need to enforce compliance where that is required".

"I want people to be confident that they can shop safely provided they follow the social distancing rules for all premises," he added.

Updating with the latest statistics, Professor Yvonne Doyle, Public Health England's medical director, said in any week recently 61,000 people might have been infected with coronavirus, adding that that is a "fairly stable" figure.

She said the R number, showing the reproduction of the virus, is estimated to be between 0.7 and 1.

Boris Johnson said he regretted the "confusion and anger" caused by the Dominic Cummings row.

At the daily Downing Street press conference, the Prime Minister said: "Do I regret what has happened? Yes, of course I do regret the confusion and the anger and the pain that people feel."

He added: "This is a country that has been going through the most tremendous difficulties and suffering in the course of the last 10 weeks and that's why I really did want people to understand exactly what had happened."

The Prime Minister said he had been told about Dominic Cummings' decision to drive to Durham to isolate while he was himself ill and "had a lot on my plate".

"I didn't know about any of the arrangements in advance," Boris Johnson told the Downing Street press conference.

"What I think did happen was while I was ill and about to get a lot sicker we had a brief conversation in which I think Dominic Cuimmings mentioned where he was.

"But I have to tell you, at that particular stage I had a lot on my plate and really didn't focus on the matter until these stories started to emerge in the last few days."

Mr Cummings said he had to drive for half an hour on Easter Sunday to test his eyesight before making the long trip back to London.

Mr Johnson was asked why the Government had not laid on a car for Mr Cummings to return to the capital.

The PM said: "To the best of my knowledge, Mr Cummings has just subjected himself to your interrogation for quite a long time now about these very detailed matters and has produced quite a substantial chunk of autobiography about what happened in the period from March 27 to April 14.

"I really feel that it would be wrong of me to try to comment further. I think people will have to make their minds up. I think he spoke at great length. To me, he came across as somebody who cared very much about his family and who was doing the best for his family.

"I think, as he said himself, reasonable people may disagree about some of the decisions that he took, but I don't think reasonable people can disagree about what was going through his head at the time and the motivations for those decisions."

Mr Johnson said local authorities were ready to make sure people being quarantined on entering the UK were "well looked after".

But when asked by a member of the public what capacity was available for providing food and medical essentials Mr Johnson could not say what will be in place.

He added: "I cannot tell you what provisions we have yet made for people self-isolating, whether they will receive food and provisions.

"Possibly it will be reasonable to assume that they come into the UK knowing the rules, they will take steps to self-isolate somewhere where they can make sure that they are provided it all.

"But if not local authorities are ready to make sure they are well looked after."