Plans are being drawn up for football matches, theatre performances, concerts and wedding receptions to trial the impacts of reopening of the economy.
Volunteers will be invited to attend experimental events, including conferences, sporting fixtures and nightclub discos, before their doors are opened more widely to the public.
At least 10 trials are due to take place, starting in April.
The tests are seen as crucial to exploring the effects on coronavirus transmission of reopening key sectors.
Sources told The Times that Downing Street wanted a consistent approach to relaxing curbs and a decision on whether rules could be eased would "depend on the outcome of this work".
Meanwhile, Downing Street played down suggestions that European football's governing body was considering holding this summer's Championships entirely in England following Britain's successful vaccination drive.
A No10 spokesman said: "This is just speculation – how the tournament will be hosted is a matter for Uefa.
"As they stated yesterday, they remain committed to the current format of the tournament.
"We are focused on the matches we are scheduled to host in the UK, including seven at Wembley and matches also being hosted at Hampden Park in Glasgow."
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Britain was today warned “do not wreck this now” after evidence that people are starting to break lockdown rules.
It came on the day it was confirmed that the next stage of the vaccination programme will be prioritised by age, with teachers and other key workers having to wait.
Today’s Downing Street briefing delivered a sobering message before a weekend when much of the country is expected to be bathed in sunshine.
Prof Jonathan Van-Tam presented testing data showing cases rising in one in five local authority areas.
The deputy chief medical officer warned: “Please don’t be tempted to think ‘well, one home visit might be all right, the weather ’s getting better, it’s going to be a nice weekend’.
“There are some worrying signs that people are relaxing, taking their foot off the brake at exactly the wrong time.
"It’s a bit like being 3-0 up in a football game and thinking, well, we can’t possibly lose this now.
"But how many times have you seen the other side take it 4-3.
“Do not wreck this now, it is too early to relax.
"Just continue to maintain discipline and hang on just a few more months. We are so close.”
He added: “I do worry that people think it’s all over.”
'Data not dates has turned into dates not data'
Meanwhile Boris Johnson has been criticised by the Government’s own behavioural advisors for including specific dates in his roadmap out of lockdown.
Prof Stephen Reicher, of the University of St Andrews said that “data not dates, has turned into dates not data”.
He is a member of SPI-B, the behavioural science subgroup of the Scientific Advisory Group for Emergencies (Sage).
He highlighted the choice of June 21 Midsummer Day for a possible return to normality, adding: “Once you announce clear dates you create facts on the ground which alter the reality.
“You create a situation [where] it’s very difficult to shift from those dates.
“It gives hope if you can stick to those dates.
"If you don’t it brings despair.
"And it’s a dangerous strategy.”
Proof that people were already using the dates to plan was seen in the huge surge in holidaybookings and the announcement of events such as the Reading and Leeds festival, he said.
Prof Susan Michie, who also sits on SPI-B, said there was too much uncertainty to predict beyond March.
“Yet again [Johnson] is raising expectations that may be dashed,” she said.
“And yes, again, he calls it a roadmap but it’s still not a coherent strategy.”
