U.K. Prime Minister Boris Johnson announced a modest easing of the country’s coronavirus lockdown Sunday and outlined his government’s road map for further lifting restrictions in the coming months.

In a televised address to the nation, Johnson said people in Britain who can’t work from home, such as those in construction or manufacturing jobs, “should be actively encouraged to go to work” this week.

However, he said they should not travel by public transport and should abide by social distancing guidelines when at work.

Johnson said that starting Wednesday, a restriction limiting outdoor exercise to once a day will be lifted and that people will be able to take “unlimited amounts.”

He said people will be able to sunbathe, drive to other destinations, and resume playing sports, but only with members of the same household. He did add that fines will be increased for the few who break the rules.

The prime minister, who spent a week in the hospital receiving treatment for COVID-19, stressed that everyone must carry on abiding by social-distancing rules when out in public and that fines for flouting them will be increased.

Johnson said his government was able to make some changes in the lockdown conditions it set because coronavirus-related deaths in the U.K. are declining along with hospital admissions of patients with the virus. But he said it would be “madness now to throw away that achievement by allowing a second spike.”

Johnson also laid out a “conditional plan” for relaxing other lockdown restrictions in the coming months, including the possible return to school for some younger children on June 1.

As anticipated, Johnson also announced the introduction of a new alert system, which will be ranked from one to five. Level one would mean the disease is not present in the UK anymore and five is the highest level.

The alert system orients itself at the R-number, with R referring to the reproduction rate, which measures the average number of people that a person infected with Covid-19 contaminate. The goal was to keep this number below 1.0. It is currently at an estimated 0.5 to 0.9. “Whatever we do, we must take care that the R does not exceed one,” he said.

The new system will be able to detect local flare-ups and give a national picture. Lockdown measures can then be adjusted accordingly.

However, he said, “this is not the time to simply end the lockdown this week. Instead, we’re taking first careful steps to modify the measures.”

Instead, the level of R will be monitored every day. The easing of any lockdown measures will be conditional to that factor.

Step two, Johnson said marks the phased reopening of shops and allowing primary pupils back into school.

Step three will happen in July the earliest and its implementation will be subject to all conditions and scientific advice. That phase will see more children being sent back to school and the opening of some hospitality services.

“We’re going to be driven by science, data, and public health,” he said. The goal is to “keep that R down.”

Johson briefly mentioned that people who will arrive in the UK by air will be quarantined for 14 days.

“If there are outbreaks, we will not hesitate to put on the brakes. We’ve been through the initial peak but it’s coming down the mountain that is often more dangerous” Johnson stressed.

“If we can’t do it by those dates, we will simply carry on until we got it right.”

The U.K. government has replaced its “stay at home” coronavirus slogan with a new “stay alert” message, raising concerns about the potential danger of mixed messaging.

The government-ordered lockdown, which began March 23, has reduced the transmission of the virus, but the daily death toll remains uncomfortably high. The U.K. recorded nearly 32,000 deaths as of Sunday, the most in Europe and the second-highest pandemic toll worldwide.

Johnson, who returned to work only two weeks ago following his hospitalization for COVID-19, is expected to announce in a prerecorded televised address only modest changes to the lockdown terms in England The devolved governments in Scotland, Wales and Northern Ireland have already extended the lockdown for another three weeks.

Ahead of his speech, Johnson sought to flesh out the meaning of the new “stay alert” slogan as telling the public to “stay at home as much as possible,” to keep two meters (over 6 feet) apart “where possible” when going out and to limit contacts with other people.

The leaders of Scotland, Wales, and Northern Ireland said they would retain the “stay at home” message. Up until now, the four nations of the U.K. have moved in lockstep on virus regulations.

Scottish First Minister Nicola Sturgeon said she didn’t know what the new advice meant and that she has asked the U.K. government not to promote what she considers to be a “vague and imprecise” message in Scotland.

“There is always a risk of mixed messaging,” the first minister said during a press briefing. “The default stay at home message remains.”

Health experts also expressed concern that the new slogan lacks clarity and may lead to an increase in “risky behavior” by the public that could cause infections to accelerate again and produce a second peak in coronavirus-related deaths.