Boris Johnson has said he is still suffering the symptoms of coronavirus after being admitted to hospital, more than a week after he first tested positive for the disease.

The Prime Minister remains under observation at St Thomas' hospital in London where he was said to be continuing to work on his official papers from his hospital bed.

In a tweet, the PM said that he was in "good spirits" after being taken to hospital on the advice of his doctor to undergo some "routine tests".

"Last night, on the advice of my doctor, I went into hospital for some routine tests as I'm still experiencing coronavirus symptoms," he said.

"I'm in good spirits and keeping in touch with my team, as we work together to fight this virus and keep everyone safe."

Earlier Mr Johnson's official spokesman said he continued to lead the Government after spending a "comfortable" night.

The spokesman, however, declined to give details of any treatment he had received or when he might be discharged.

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

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."

The spokesman dismissed a report in Russian state media that Mr Johnson was on a ventilator as "disinformation".

"Our specialist Government units have seen a rise in false and misleading narratives since the coronavirus pandemic started. It's vital that any disinformation is knocked down quickly," the spokesman said.

US President Donald Trump was among those wishing the Prime Minister well, describing him as "a great friend of mine" and adding: "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.