The coronavirus lockdown is to be extended for at least another three weeks, Foreign Secretary Dominic Raab has said as he warned that lifting restrictions now would risk a dangerous second peak of Covid-19.

Mr Raab, who is deputising for Prime Minister Boris Johnson as he recovers from the virus, said the original three-month timeline set down by Mr Johnson to come through the peak of the virus was broadly “still the outline”.

Later on Thursday people around the country participated in the fourth clap for carers, including Mr Johnson, who is recovering at his country residence, Chequers, with Mr Raab and Chancellor Rishi Sunak taking part in Westminster.

Mr Raab told reporters at the daily Downing Street press conference there is “light at the end of the tunnel” but refused to set out a “definitive timeframe” for easing the lockdown measures, stressing that lifting them now would only lead to a “second lockdown”.

He said: “The Prime Minister said at the outset that it would take three months to come through the peak and I think that, broadly, is still the outline.

“We can’t give a definitive timeframe, that would be to prejudge the evidence, that wouldn’t be a responsible thing to do.

“But our message to the British public is: there is light at the end of tunnel, we are making progress, but at the same time we must keep up the social distancing measures.”

Mr Raab said ministers and scientists must be confident there will be no second wave of infections, and that more widespread testing needed to be put in place alongside solid evidence that infections were falling.

“The worst thing we could do right now is to ease up too soon, allow a second peak of the virus to hit the NHS and to hit the British people”, he said at the daily press briefing.

“It would be the worst outcome not just for public health but for the economy and for our country as a whole.”

Mr Raab said there were still “issues with the virus spreading in some hospitals and in care homes”, adding: “The very clear advice we received is that any change to our social distancing measures now would risk a significant increase in the spread of the virus.

“That would threaten a second peak of the virus and substantially increase the number of deaths.

“It would undo the progress we have made to date and as a result would require an even longer period of the more restrictive social distancing measures.”

Mr Raab said the Government needed to be satisfied of five things before it would consider it safe to adjust the current measures.

They are:

– Protect the NHS’s ability to cope and be confident that the NHS is able to provide sufficient critical care across the UK

– A sustained and consistent fall in daily death rates to be confident the UK is beyond the peak

– Reliable data from Government scientific advisers showing rate of infection is decreasing to manageable levels across the board

– Confidence that testing capacity and personal protective equipment (PPE) are in hand with “supply able to meet future demand”

– Confidence that any adjustments to the current measures would not risk a second peak in infections.

Mr Raab said the rate of infection – the R0 value – was “almost certainly below one in the community”, meaning infected people were passing the disease on to fewer than one other person on average.

“But overall we still don’t have the infection rate down as far as we need to,” he said.

Ministers agreed the need to prolong social distancing measures following meetings of the Cabinet and the Government’s emergency committee Cobra.

But Wales’s First Minister Mark Drakeford announced the decision to extend lockdown before Mr Raab.

It comes as the Department of Health said the Covid-19 death toll in hospitals in the UK had reached 13,729 as of 5pm on Wednesday, up 861 on the figure the day before.

Earlier, Health Secretary Matt Hancock warned it will take time for life to return to normal as a Government scientific adviser questioned whether ministers had done enough work on an exit strategy.

Professor Neil Ferguson from Imperial College London said: “I think there’s a lot of discussion. I would like to see action accelerated.”

Speaking on BBC Radio 4’s Today programme, Prof Ferguson called for more co-ordination, adding that “we have limited leeway to release current measures unless we have something new to put in their place”.

He said before restrictions are eased, more testing will be needed to isolate individual cases and trace their contacts to keep future outbreaks under control.

“And I should say, it’s not going to be going back to normal,” he added.

“We will have to maintain some form of social distancing, a significant level of social distancing, probably indefinitely until we have a vaccine available.”

On Wednesday evening, health minister Nadine Dorries used Twitter to urge journalists to stop calling for an exit strategy, adding: “There is only one way we can ‘exit’ full lockdown and that is when we have a vaccine.”

England’s chief scientific adviser Sir Patrick Vallance said on Thursday the way out of the current situation was vaccines and therapeutics.

“Those are going to be critically important,” he said.

Elsewhere, captain Tom Moore, 99, who has walked 100 lengths of his garden to generate cash for the NHS was praised as “an inspiration to us all” as his fundraising campaign passed the £16 million mark.

The Office for National Statistics (ONS) also released data confirming the death rate for men with coronavirus in England and Wales is twice as high as that of women.

Downing Street confirmed a review will take place into why people from black, Asian and minority ethnic (BAME) backgrounds appear to be disproportionately affected by coronavirus.

And a plane carrying Romanian fruit and vegetable pickers arrived in the UK to keep up with demand.