“We want, if we possibly can, to get going with some of these measures on Monday,” the prime minister told the House of Commons.
The comment came as Mr Johnson confirmed that his long-awaited roadmap of options for escaping the lockdown will be unveiled on Sunday – three days after the review required by law.
Downing Street said that Mr Johnson’s announcement on Sunday will deal only with social distancing measures, and not the package of financial support for businesses provided by the Treasury during the lockdown. Chancellor Rishi Sunak is reported to be planning a statement next week to unveil moves to roll back the “furlough” arrangements under which the state pays up to 80 per cent of salaries for staff who would otherwise be laid off.
The prime minister’s comments could herald changes designed to get more businesses up and running and more people back to work. But social distancing instructions for individuals – requiring people to stay two metres apart and not mix with other households – are expected to remain in place for longer.
Mr Johnson explained: “It would be an economic disaster if we pursue a relaxation of these measures now in such a way as to trigger a second spike.”
Housing secretary Robert Jenrick later made clear that Sunday's announcement will focus on measures to get the economy moving again.
“Every local economy now needs a plan to restart and recover,” he said at the daily Downing Street coronavirus briefing.
“We will be informing these plans with our own detailed work in areas such as: how workplaces from factories to construction sites to offices can be adapted; how outdoor spaces, leisure and businesses from parks to high streets to markets can be managed; and how public transport networks from the Tube to trams to buses can operate.
“In each case, guided by scientific and medical advice, we want to ensure appropriate and safe social distancing, providing the public with the confidence to return to work and to return to public spaces and public transport knowing that it is always safe to do so.”
Meanwhile, health secretary Matt Hancock suggested that one possible relaxation could allow cafes to open if they only served customers sitting outdoors, where the infection risk is far lower.
Downing Street appeared to foreshadow a change in advice by using a “stay safe, save lives” hashtag on its Twitter feed in place of the “stay home, save lives” message it has promoted over the past six weeks. Public Health England was reported to have emailed orders to drop the “stay home” message from communications from Saturday evening as authorities prepare to move to a “new phase”.
Mr Johnson’s spokesperson declined to comment on the PHE message and played down the significance of the Twitter slogan, telling reporters: “We have used a variety of messaging across social media since we began this phase of the response.”
The government has a legal obligation to conduct a six-week review of lockdown restrictions on Thursday, when ministers are due to hold a virtual cabinet meeting.
But No 10 indicated that this may result in no more than a statement that the review has been conducted and measures are staying in place pending a further announcement on Sunday.
The PM’s spokesman said it was possible that further expert scientific and medical advice submitted after the review deadline may have to be taken into account, and cabinet could meet again on the weekend.
“There’s a deadline tomorrow in terms of having to carry out a review,” said the PM’s spokesman. “We will want to ensure we get any subsequent announcement right and if that means taking a little extra time then that’s what we will do.”
The spokesman indicated that Mr Johnson will not be setting out a firm timetable for the removal of various restrictions in his statement on Sunday.
“If you are going to point towards a potential date, you want to feel confident that you are going to be able to make those changes on the dates you have given,” he said
And he cautioned that any relaxation of lockdown will be gradual: “Everything is not going to be able to return to normal all at once. This is not going to be a case of flicking a switch. People will have to prepare for a different type of normal.”
Any “easements” in the lockdown conditions will be monitored carefully to ensure they are not creating the risk of an increase in the rate of infections and a rise in the reproduction measure –known as R – towards the critical point where each infected person passes the disease on to more than one other person.
Mr Jenrick said that any relaxation of lockdown could be reversed in localised areas if there are signs of the virus again flaring up.
He played down the prospect of a phased exit from controls in different parts of the country, but added: "If, as we build up our infrastructure for testing and tracking and tracing, in time it is required for us to make interventions in smaller micro-communities where you are seeing the virus take hold again, then that will be something that we consider."
The housing secretary declared: "Our mission is to ensure everything we can is done to help people to get back to work safely, to reunite friends and family and to reintroduce the things that make life worth living in a safe way as soon as it's safe to do so."
After Commons Speaker Sir Lindsay Hoyle voiced his annoyance that the exit strategy statement would be made to TV cameras rather than MPs, Mr Johnson pledged that a government minister would make a statement and answer questions in the chamber on Monday.
But he dodged a demand from Keir Starmer for the statement to be made by Mr Johnson personally.
The PM said the delay until Sunday was “very simple”, allowing the government to assess new scientific data and prepare the public for any changes on the first working day of the week.
“We have to be sure that the data is going to support our ability to do this,” the prime minister said.