The lockdown is facing a major test from a long weekend of warm weather, and concerns of mixed messaging ahead of Boris Johnson’s announcement on easing restrictions.

Foreign Secretary Dominic Raab said “any changes in the short term will be modest, small, incremental” before the Prime Minister’s address to the nation on Sunday evening.

Mr Raab admitted there could be minor rifts in efforts to maintain a UK-wide approach to tackling Covid-19, with Wales set to announce plans on Friday.

But he told on the public that the rules had not yet changed ahead of the long weekend to mark 75 years since VE Day, when victory was declared in Europe during the Second World War.

“For the moment it is really important, particularly as people look towards a warm bank holiday weekend, that we continue to follow the guidance in place at this time,” Mr Raab said.

Labour leader Sir Keir Starmer said “we owe so much to the generation of VE Day” as he warned of tragedy in care homes where Covid-19 is spreading.

“The crisis in our care homes has gone on for too long and we must do everything we can to protect our most vulnerable, many of whom protected our country in its darkest hour,” he wrote in the Telegraph.

His plea came after it emerged the R value – the number of people the average infected individual would spread the virus to – had risen to between 0.75 and 1.0 because of the spread in care homes.

Mr Raab said ministers are “confident” they can decrease the infection rates in hospitals and care homes, where the value is larger than the community.

Government efforts to lower the R value with protective equipment, testing and contact tracing directly affect how measures can be eased because if it raises above one, the virus will spread rapidly.

With official data suggesting more than 36,000 people have died with coronavirus in the UK, the PM will unveil his “roadmap” for easing the lockdown in a broadcast to the nation at 7pm on Sunday.

But there are tensions between ministers and the devolved administrations in Scotland and Wales.

Welsh First Minister Mark Drakeford will announce his own plans during a press conference at 12.30pm on Friday.

His Scottish counterpart, Nicola Sturgeon, warned she would not be “pressured” by the Westminster Government into “prematurely” easing restrictions in Scotland.

Mr Raab echoed a message from Downing Street in acknowledging that “different parts may move at slightly different speeds”.

The Welsh Government warned of the danger of sending out “mixed messages”, after newspaper reports suggested sunbathing and picnics could be permitted as early as Monday.

A member of the Scientific Advisory Group for Emergencies (Sage), which is informing the coronavirus response, also warned leaked information is “incredibly damaging”.

“If people are primed to look at things in a certain way, it will shape how they receive the information. So on Sunday they will be looking for the green lights and they won’t notice the red lights. It’s a really powerful way of influencing people,” they told the Guardian.

In other developments on the eve of VE Day:

– The Royal Hospital Chelsea said nine Chelsea Pensioners had died of coronavirus-related conditions

– Tests continued to stay below the 100,000-a-day target, with 86,583 conducted in the 24 hours to 9am on Thursday

– The nation clapped from their windows and doorsteps for the seventh week in a row to show their appreciation of NHS workers and other carers.

Officials will scrutinise the latest data on the spread of the disease, and ministers are expected to convene over the weekend before details are finalised for Sunday’s announcement.