Boris Johnson is still in hospital under observation but had a "comfortable" night after being admitted on Sunday with persistent coronavirus symptoms, Downing Street has said.

Mr Johnson's official spokesman said he continued to lead the Government and had been working on official papers from his bed.

The Prime Minister was said to be in "good spirits" after being taken to St Thomas' Hospital in London as a "precaution".

He remains under observation and the spokesman declined to give details of any treatment he had received or when he might be discharged.

"The Prime Minister was admitted to hospital for tests last night as a precaution. The issue is that his symptoms remain persistent," the spokesman said.

He added: "The Prime Minister had a comfortable night at St Thomas' Hospital in London and is in good spirits. He remains in hospital under observation."

In Mr Johnson's absence, the daily government coronavirus meeting was chaired by Dominic Raab, the Foreign Secretary and First Secretary of State.

However, the PM's spokesman said that he had received his ministerial red box containing his official papers and was continuing to work from hospital.

"He continues to receive a box. The Prime Minister remains in charge of the Government."

Mr Johnson was tested positive for coronavirus on March 27 and had been self-isolating in the Downing Street flat.

The decision to admit him to hospital was taken on the advice of his doctor as the symptoms of a cough and a high temperature continued to persist more than a week after his original diagnosis.

An ambulance was not called and the spokesman said he was taken the short distance from No 10 by "private transportation" but declined to give any further details.

The spokesman stressed, however, that it was "not an emergency admission".

Downing Street also denied Russian media reports that the PM had been placed on a ventilator.

"His care will be dictated by the doctors who are looking after him," the spokesman said.

Meanwhile, England's chief medical officer Professor Chris Whitty has recovered from his coronavirus symptoms and is back at work.

Earlier, Communities Secretary Robert Jenrick said that Mr Johnson was expected to be back in Downing Street "shortly".

"He's been working extremely hard leading the Government and being constantly updated," he told BBC Breakfast.

"That's going to continue.

"Obviously today he's in hospital having the tests but he will continue to be kept informed as to what's happening and to be in charge of the Government.

"I'm sure this is very frustrating for him, for somebody like Boris who wants to be hands on running the Government from the front, but nonetheless he's still very much in charge of the Government."

US President Donald Trump was among those wishing the Prime Minister well, describing him as "a great friend of mine" and adding: "I'm sure he is going to be fine, he's a strong man, a strong person."

However the former head of the civil service Lord Kerslake has said it may be "sensible" for Mr Johnson to "step back" if he is not well enough to carry out his role for now.

"I think in the end if he's not well, he will have to reflect on this because the job's tough at the best of times and it's doubly tough now," he told the BBC Radio 4 Today