Boris Johnson has tested positive for coronavirus and is self-isolating in Downing Street, it has been announced.

The Prime Minister, 55, was tested in Number 10 after experiencing mild symptoms on Thursday.

In a video on his Twitter account, Mr Johnson said he had developed a temperature and a persistent cough.

He added: “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.

“I want to thank everybody involved and, of course, our amazing NHS staff.”

A Downing Street spokeswoman said the PM was tested on the personal advice of England’s chief medical officer, Professor Chris Whitty.

She added: “The test was carried out in No 10 by NHS staff and the result of the test was positive.

“In keeping with the guidance, the Prime Minister is self-isolating in Downing Street.

“He is continuing to lead the government’s response to coronavirus.”

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Prime Minister Boris Johnson arrives for a press conference with Chief Medical Officer for England Chris Whitty

It is not known whether he is staying with his fiancee, Carrie Symonds, who is several months pregnant.

Earlier in the week it was announced that the Prince of Wales was also suffering “mild symptoms” of the disease.

On Thursday night Charles was seen for the first time since testing positive.

Clarence House posted a video in their Instagram Stories of heir to the throne Charles joining in with the round of applause for the NHS from Birkhall, his private home on the Balmoral estate in Scotland.

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Screen grab from the Instagam story of @clarencehouse of the Duchess of Cornwall and the Prince of Wales joining in the national applause for the NHS workers

Mr Johnson’s positive test was announced as:

– Police began fining people breaching coronavirus lockdown rules, less than 24 hours after new laws were brought into force.

– GP Habib Zaidi, 76, who died at Southend Hospital in Essex, is feared to have become the first doctor in the UK to have died after contracting coronavirus.

– Sports Direct founder Mike Ashley has apologised for “ill-judged and poorly timed” emails after the businessman faced fierce criticism when he tried to claim Sports Direct was an essential operator for keeping the nation fit.

– UK supermarkets said they will use a government database of 1.5 million vulnerable shoppers to help prioritise delivery slots.

– Labour MP Angela Rayner announced on Twitter that she is self-isolating after suffering symptoms, while Duncan Selbie, the chief executive of Public Health England, is also self-isolating with symptoms.

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Prime Minister Boris Johnson and Chancellor Rishi Sunak outside 10 Downing Street, London, joining in with a national applause for the NHS

On Thursday night Mr Johnson applauded the NHS outside Downing Street a couple of metres away from Chancellor Rishi Sunak.

Mr Johnson’s Cabinet took place remotely on Tuesday with ministers using using Zoom video conferencing.

Downing Street had previously confirmed that Foreign Secretary Dominic Raab would stand in if Mr Johnson was too unwell to continue.

If Mr Raab was also ill, the PM has the power to delegate responsibility to any of his ministers.

Mr Johnson has been working closely with the medics leading the fight against the spread of the virus, including Prof Whitty, Deputy chief medical officer Dr Jenny Harries and Chief scientific adviser Sir Patrick Vallance.

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The Queen speaking to Prime Minister Boris Johnson from Windsor Castle

A Buckingham Palace spokesman confirmed the Queen last saw Mr Johnson just over two weeks ago.

He said: “Her Majesty the Queen remains in good health. The Queen last saw the Prime Minister on the 11th March and is following all the appropriate advice with regards to her welfare.”

Their following meeting, held on March 18, was conducted via telephone as have their subsequent conversations.