Downing Street said the Prime Minister is making a good recovery following his operation on Monday morning.
It is understood Deputy Prime Minister Dominic Raab remains on hand to assist with any major decisions, in line with the general advice to the public on not making significant choices for the first 24 hours after undergoing general anaesthesia.
However, Boris Johnson remains Prime Minister and will continue acting as such, No 10 said.
Boris underwent a “very minor routine operation related to his sinuses” at a London hospital on Monday morning, Downing Street has said.
The Prime Minister’s official spokesperson said: “He went to hospital around 6am and the operation was carried out first thing this morning.
“He was back in Downing Street shortly after 10am.”
Asked how the Prime Minister was feeling, the spokesman said he had not spoken to him since his return to Downing Street but that he was resting at home.
Boris Johnson
Joe Giddens
The timing of Mr Johnson’s return to work would depend on how he feels, but he was planning to chair Tuesday morning’s Cabinet meeting, according to the spokesperson.
Asked who was in charge of the UK nuclear accounts during the procedure, the spokesperson said Deputy Prime Minister Dominic Raab and Cabinet Secretary Simon Case were aware in advance and that Mr Johnson was under for a “relatively brief time”.
Procedures were in place so that any significant decisions could be deferred to Mr Raab before Mr Johnson resumed duties, the spokesman said.
They said: “Should significant decisions need to be made it would be for the deputy prime minister at the moment.”
The operation was on the NHS and was scheduled “for a while”, he said, without specifying at which hospital it took place.
Mr Johnson’s sinus issue was not understood to be related to his Covid illness in 2020.