The coronavirus lockdown measures are likely to be extended beyond three weeks, a Cabinet minister has said, as senior figures dealing with the response are set to discuss a review of the restrictions.

After Boris Johnson spent a third night in intensive care, Foreign Secretary Dominic Raab will deputise for him by chairing a Cobra emergency committee on Thursday afternoon to discuss the lockdown measures with leaders of the devolved nations.

No decision is expected to be made at that meeting in the Prime Minister’s absence, with key figures dealing with the response instead discussing whether to ease or strengthen the measures ahead of an announcement next week.

But there seems little chance of the lockdown being lifted with the PM remaining in intensive care and Wednesday having witnessed a rise of 938 in the number of deaths in UK hospitals of patients who tested positive for Covid-19, the highest new total so far.

However, the restrictions face their toughest test so far over the Easter weekend, with temperatures in some parts of the country set to reach 25C (77F) threatening to tempt more people to break the stay-at-home rules.

Culture Secretary Oliver Dowden urged the public not to give up on the measures during the test of the long weekend as he predicted they would not be eased next week.

“I don’t think it’s very likely these measures are going to be changed given they’re just starting to have an effect but, as we said, we would review them,” he told BBC News.

“It’s only prudent that on an ongoing basis we review them after three weeks.”

Mr Dowden insisted the reason to hold off on making the decision until next week was because they were following the “proper process”, and not because ministers are waiting for the return of the PM, who he described as doing “reasonably well” in a stable condition.

Wales has already announced an extension of lockdown measures, and Welsh health minister Vaughan Gething said there is “virtually zero prospect” of experts advising that UK-wide measures can be eased yet, which he said would remain in place for “a number of weeks”.

The PM committed to a review at the three-week mark, which will be reached on Monday, but Downing Street now says it will take place “on or around” that point.

Emergency legislation designed to assist with Covid-19’s containment must also be reviewed at least once every 21 days – with the first due to be carried out by April 16 at the latest.

Chancellor Rishi Sunak earlier sidestepped questions about the prospect of different parts of the UK emerging from the lockdown at different times.

Deputy chief scientific adviser Professor Dame Angela McLean said she suspected “simple strategies might well turn out to be the best to use”.

Welsh First Minister Mark Drakeford said the lockdown will not end in Wales next week, insisting “we will not throw away the gains” by “abandoning our efforts just as they begin to bear fruit”.

Debate about the restrictions took place as Downing Street offered more hopeful news about the PM’s condition in St Thomas’s Hospital on Wednesday.

Number 10 said Mr Johnson remains in intensive care but is making “steady progress”, with further updates expected on Thursday.

Mr Sunak had said the PM was “sitting up in bed” and “engaging positively” with the medics treating him for Covid-19.

But the boost came as the nation saw its record number of deaths in hospitals, with a rise of 938 taking the toll to at least 7,097, according to Department of Health figures.

Though significantly larger than the previous highest toll of 786, Prof McLean said new cases are not “accelerating out of control”.