Stanley Johnson said the whole family was ‘amazingly grateful’ for the efforts of the NHS and for the huge outpouring of support for his son. He said the Prime Minister’s illness had underlined just how serious the coronavirus outbreak was.

‘To use that American expression, he almost took one for the team. We have got to make sure we play the game properly now,’ he told the BBC Radio 4 Today programme.

He played down suggestions that his son would now quickly return to work at Downing Street. He said: ‘This is pretty straightforward now. He must rest up. As I understand it, he has moved from the ICU into a recovery unit but I don’t think you can say this is out of the wood now.’

‘He has to take time. I cannot believe you can walk away from this and get straight back to Downing Street and pick up the reins without a period of readjustment.’

Mr Johnson was moved out of intensive care last night and returned to the ward at St Thomas’ Hospital as his condition continues to improve.

A No 10 spokesman said ‘The Prime Minister has been moved this evening from intensive care back to the ward, where he will receive close monitoring during the early phase of his recovery. He is in extremely good spirits.’

Good wishes flooded in for the Prime Minister from colleagues, the Labour leader Sir Keir Starmer and from US president Donald Trump.

The news came less than an hour before the country came together for the weekly Clap for Carers at 8pm on Thursday evening.

Mr Johnson was originally admitted to hospital on Sunday on the advice of his doctor, amid concerns he was still suffering symptoms 10 days after testing positive for Covid-19.

Initially it was described as a ‘precautionary’ measure and on Monday he was said to be issuing instructions and working on his ministerial red boxes from his hospital bed.

But by the evening his condition had deteriorated and he was moved to the intensive care unit in case he required a ventilator.

The announcement was greeted with shock at Westminster amid fears that No 10 had sought to play down the seriousness of his condition.

The Prime Minister’s official spokesman said that while he had received oxygen treatment, he had not needed to be put on a ventilator or Continuous Positive Airway Pressure machine.

By Wednesday he was said to have been well enough to sit up in bed and to communicate with his medical team.

Earlier on Thursday, Foreign Secretary Dominic Raab, who has been deputising for Mr Johnson, told the daily No 10 press conference that the PM had been making ‘positive steps forward’.

After the news that the PM had left intensive care was announced, Mr Raab declared it ‘the news we all wanted to hear’.

‘Thank you to all the NHS staff helping the country and the PM to beat #coronavirus. Together we can all do our bit by staying home and protecting the NHS #StayHomeSaveLives,’ he added.

Mr Johnson’s fiancee, Carrie Symonds, tweeted a string of clapping emojis a short time later as she joined in the Clap For Carers campaign.

Health Secretary Matt Hancock said: ‘So good that the Prime Minister is out of intensive care and on the road to recovery’, while Sir Keir welcomed the ‘good news’.

Mr Trump also sent a message of support to the Prime Minister, tweeting: ‘Great News: Prime Minister Boris Johnson has just been moved out of Intensive Care. Get well Boris!!!’