Boris Johnson improving, sitting up now: Chancellor Sunak

Johnson was now "sitting up in bed and engaging positively with the clinical team", Sunak said at a daily coronavirus media briefing here.

The Indian-origin Sunak said Mr Johnson was "receiving excellent care from the NHS team at St Thomas'".

"The Prime Minister is not only my colleague and my boss but also my friend and my thoughts are with him and his family," he added.

Earlier, Johnson's spokesman said that he was "responding to treatment" while being kept at hospital for close monitoring" and remained clinically stable.

Downing Street said he was not working but could contact those he needed to.

Johnson was admitted to St Thomas' on Sunday, on the advice of his doctor, after continuing to have a cough and high temperature 10 days after testing positive for the virus. He was given oxygen before being taken to intensive care on Monday.

Downing Street said Johnson was in "good spirits" on Wednesday as he continued to receive standard oxygen treatment. He was breathing without any assistance, such as mechanical ventilation or non-invasive respiratory support The UK on Wednesday saw a record 938 daily deaths, taking the total number of UK deaths now stands at 7,097, according to the latest Department of Health figures.