Johnson was admitted to hospital on Sunday which Downing Street said was a precautionary measure, with his symptoms not clearing after a week.
But this evening it has emerged he has been transferred to intensive care and Dominic Raab, the first secretary of state, is going to deputise as needed.
Newly elected Labour leader Keir Starmer said it was “terribly sad news” and he was thinking of the prime minister, while SNP House of Commons leader Ian Blackford also wrote of his concern.
Terribly sad news. All the country’s thoughts are with the Prime Minister and his family during this incredibly difficult time. https://t.co/9Eh4ktiqTw
— Keir Starmer (@Keir_Starmer) April 6, 2020
So sorry to hear that @BorisJohnson is now in intensive care. This is very worrying news. Thoughts and prayers with Boris, @carriesymonds and all their family. This is such a terrible virus that we all must take seriously. Get well soon Boris, look forward to you being back.
— Ian Blackford (@Ianblackford_MP) April 6, 2020
His chancellor, Rishi Sunak, tweeted he was thinking of the prime minister and his pregnant fiancee, Carrie Symonds, who previously said she was on the mend after suffering from coronavirus symptoms.
Trade secretary Liz Truss said she was wishing for a speedy recovery.
— rishisunak (@RishiSunak) April 6, 2020
My thoughts are with the Prime Minister and his family as he is moved into intensive care this evening. Wishing him a speedy recovery.
— Liz Truss (@trussliz) April 6, 2020
Sajid Javid, who resigned as chancellor earlier this year, and former leadership rival Jeremy Hunt added to the messages of concern.
Boris is one of the strongest people I know. Thinking of him, Carrie and his family tonight. Get well soon, the country needs you.
— Sajid Javid (@sajidjavid) April 6, 2020
Keeping fighting Boris. Whole country behind you #BackBoris
— Jeremy Hunt (@Jeremy_Hunt) April 6, 2020
Labour stalwart Harriet Harman said she hoped for his full recovery and Jess Phillips immediately tweeted of her concern for the prime minister.
— Harriet Harman (@HarrietHarman) April 6, 2020
This is very serious and I wish him nothing but a swift recovery. Take care all https://t.co/XwVWOkKZDw
— Jess Phillips MP (@jessphillips) April 6, 2020
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Labour’s David Lammy said he was thinking of Johnson’s family and friends as well as the prime minister.
Dr Rosena Allin-Khan, who has been vocal about the struggles of the NHS staff who are treating coronavirus patients, has wished him a quick and full recovery and thanked the medical staff taking care of him.
— David Lammy (@DavidLammy) April 6, 2020
I wish the Prime Minister a full and speedy recovery and thank the NHS team looking after him and everyone at St Thomas'.
Coronavirus can affect anyone, the symptoms can be really awful. Please, please, remind your friends and family to stay at home!
— DrRosena (@DrRosena) April 6, 2020
And away from Parliament, Labour mayor of London Sadiq Khan praised the St Thomas’ Hospital staff, where the Prime Minister is being treated, while Scottish first minister Nicola Sturgeon and Nigel Farage, leader of the Brexit Party, added to the outpouring of support.
— Sadiq Khan (@SadiqKhan) April 6, 2020
My thoughts are with the PM and his family - sending him every good wish https://t.co/tjpadJq6bq
— Nicola Sturgeon (@NicolaSturgeon) April 6, 2020
I hope and pray for @BorisJohnson to come through this ordeal quickly.
— Nigel Farage (@Nigel_Farage) April 6, 2020
Ex-prime minister David Cameron showed his support for the prime minister while Ursula von der Leyen the president of the EU’s European Commission, and Brexit negotiator Michel Barnier, who has recovered from coronavirus himself, tweeted.
— David Cameron (@David_Cameron) April 6, 2020
My thoughts are with Prime Minister @BorisJohnson and his family this evening. I wish him a speedy and full recovery.
— Ursula von der Leyen (@vonderleyen) April 6, 2020
Wishing @BorisJohnson all the best and a speedy recovery. My thoughts are with you and your family.
— Michel Barnier (@MichelBarnier) April 6, 2020
A spokesperson for Downing Street said: “Over the course of this afternoon, the condition of the prime minister has worsened and, on the advice of his medical team, he has been moved to the intensive care unit at the hospital.
“The PM has asked Foreign Secretary Dominic Raab, who is the First Secretary of State, to deputise for him where necessary.”