Boris Johnson is resting after undergoing a minor operation during which he was briefly under general anesthesia, Downing Street has said.

Deputy prime minister Dominic Raab will take any “significant decisions” that are required to be made ahead of the PM returning to work on Tuesday.

The prime minister’s official spokesperson said Mr Johnson went into a hospital in London around 6am on Monday for what was a routine procedure, on the NHS, related to his sinuses.

He was back in Downing Street shortly after 10am, the spokesperson added.

Mr Raab “was aware of this in advance” and the cabinet secretary Simon Case was also aware, Number 10 said. The operation had been “scheduled for a while”.

Mr Johnson’s sinus issue was not understood to be related to his COVID illness in 2020.

Mr Raab had stood in for the prime minister at that time when he was admitted to intensive care at the height of the pandemic.

The deputy PM later told the Conservatives’ virtual party conference that he feared Mr Johnson could have died.

In relation to the latest hospital admission, Downing Street would not say whether Mr Johnson had been on a waiting list.