Boris Johnson, 55, is in intensive care at St Thomas’ Hospital. But just over a month ago he seemed relaxed about the possibility of being infected with coronavirus.

– March 3

The Prime Minister told a press conference: “I was at a hospital the other night where I think there were actually a few coronavirus patients and I shook hands with everybody, you’ll be pleased to know, and I continue to shake hands.”

– March 27

Mr Johnson revealed he has tested positive for Covid-19. Downing Street said he noticed mild symptoms the previous afternoon and received the test results at midnight.

In a video message on Twitter, he said: “I’m working from home and self-isolating and that’s entirely the right thing to do.

“But, be in no doubt that I can continue thanks to the wizardry of modern technology to communicate with all my top team to lead the national fightback against coronavirus.

Health Secretary Matt Hancock also announced he had tested positive for Covid-19, while chief medical officer Chris Whitty said he had symptoms of the disease and is self-isolating.

Some questioned why the PM had adopted a business-as-usual approach to governing after putting the rest of the UK on lockdown and he was accused of not following his own advice.

The House of Commons had continued to sit, with cabinet meetings and daily press briefings held in person throughout the first weeks of March.

– March 30

Number 10 confirms Dominic Cummings, Mr Johnson’s chief adviser, is self-isolating after developing coronavirus-like symptoms.

– March 31

Mr Johnson tweets an image of the first ever Cabinet meeting conducted entirely online.

– April 2

The PM comes out of self-isolation for a brief appearance at the door of No 11 Downing Street, where he lives, to join in the mass clapping for key workers on the frontlines of the coronavirus pandemic.

He told those gathered outside: “I am not allowed out really, I am just standing here.”

– April 3

Mr Johnson is seen in a video urging people to stay home and not to break social distancing rules as the weather warmed up, even if they were going “a bit stir crazy”.

– April 4

Mr Johnson’s pregnant fiancee Carrie Symonds, 32, said she is “on the mend” after suffering coronavirus symptoms.

Shortly after the PM’s announcement on March 27, Ms Symonds – who usually lives with him in the No 11 flat – shared a photograph of herself self-isolating in Camberwell, south London, with the couple’s dog Dilyn.

– April 5

Downing Street said Mr Johnson has been admitted to a London NHS hospital for tests as a “precautionary step” as his coronavirus symptoms persist.

– April 6

Mr Johnson tweets: “Last night, on the advice of my doctor, I went into hospital for some routine tests as I’m still experiencing coronavirus symptoms. I’m in good spirits and keeping in touch with my team, as we work together to fight this virus and keep everyone safe.

“I’d like to say thank you to all the brilliant NHS staff taking care of me and others in this difficult time. You are the best of Britain.

“Stay safe everyone, and please remember to stay at home to protect the NHS and save lives.”