The coronavirus infection rate will remain high for “weeks and weeks” if people flout social distancing rules this weekend, a scientist advising the Government has warned.

Professor Neil Ferguson, from Imperial College London, spoke as latest figures showed the recorded death toll from the virus in the UK has risen above 4,000, including a five-year-old child.

The Department of Health said the number of coronavirus-related hospital deaths stood at 4,313 as of 5pm on Friday, up from 3,605 the day before.

The DoH figures also showed that the number of new people tested daily in the UK has slipped back below 10,000. A total of 9,406 new people were reported as being tested in the 24 hours to 9am April 4.

For the previous two days, the equivalent figure was above 10,000. The total number of people in the UK tested since the outbreak began is now 183,190. The number of confirmed cases had reached 41,903 as of 9am on Saturday.

NHS England said 637 patients in England who tested positive for Covid-19 had died, bringing the total number of confirmed reported deaths in hospital to 3,939.

They were aged between five and 104, and 40 had no known underlying health condition, ranging in age from 48 to 93.

There were 212 deaths in the Midlands, more than in London, where there were 127. The North West had 97 deaths the North East and Yorkshire 73, the East of England 70, the South East 41 and the South West 17.

Prof Ferguson said earlier that while the epidemic was expected to plateau in the next week to 10 days, people’s behaviour was critical to determining what happens next.

His warning followed similar pleas by Boris Johnson and Matt Hancock for people to stick with the social distancing measures and resist the temptation to enjoy the sunshine forecast for swathes of the UK on Saturday and Sunday.

The stay-at-home calls came as:

– the Ministry of Justice said hundreds of risk-assessed prisoners within two months of their release date are to be temporarily sent home to reduce the risk of coronavirus taking hold in jails and overwhelming the NHS.

– Mr Johnson wrote to opposition party leaders including newly-elected Labour leader Sir Keir Starmer inviting them to a briefing next week and insisting “we have a duty to work together at this moment of national emergency”.

– A member of the armed forces became the first confirmed coronavirus case on the Falkland Islands.

Asked what would happen if people flout the social distancing rules this weekend, Prof Ferguson told BBC Radio 4: “That moves us to a slightly more pessimistic scenario.

“We still think things will plateau but we’ll be at quite high levels of infection for weeks and weeks rather than seeing quite a rapid decline as the type seen in China.”

He said he was “hopeful” that some of the intense social distancing measures could be substituted with rapid access to testing and contact tracing in a few weeks’ time – once case numbers are lower.

We want to move to a situation where at least by the end of May that we’re able to substitute some less intensive measures

“We want to move to a situation where at least by the end of May that we’re able to substitute some less intensive measures, more based on technology and testing, for the complete lockdown we have now,” he explained.

It comes after a pandemic modeller advising the Government warned that the lockdown measures are merely a “placeholder” and that Britain had “painted itself into a corner” with no clear exit strategy from the Covid-19 crisis.

Professor Graham Medley told The Times: “This disease is so nasty that we had to suppress it completely. Then we’ve kind of painted ourselves into a corner, because then the question will be, what do we do now?

“We will have done three weeks of this lockdown, so there’s a big decision coming up on April 13. In broad terms are we going to continue to harm children to protect vulnerable people, or not?”

Prof Medley added: “If we carry on with lockdown, it buys us more time, we can get more thought put into it, but it doesn’t resolve anything, it’s a placeholder.”

On Friday, England’s chief nursing officer, Ruth May, urged people to think of two nurses who died after contracting coronavirus and “stay home for them”.

Areema Nasreen and Aimee O’Rourke, both mothers of three children, died alongside two healthcare assistants, it was announced on Friday.

Ms May, speaking at the daily Downing Street press conference, said: “This weekend is going to be very warm and it will be very tempting to go out and enjoy those summer rays.

“But please, I ask you to remember Aimee and Areema. Please stay at home for them.”

She added: “I worry that there’s going to be more and I want to honour them today and recognise their service.”

Meanwhile, in his letter to opposition leaders, the PM said: “As party leaders, we have a duty to work together at this moment of national emergency.

“Therefore, I would like to invite all leaders of opposition parties in Parliament to a briefing with myself, the chief medical officer and chief scientific adviser next week.

“I want to listen to your views and update you on the measures we have taken so far, such as rapidly expanding testing and providing economic support to businesses and individuals across the country.”