Friends of Boris Johnson believe he is worried about how to afford a nanny after taking a pay cut to become prime minister on a salary of around £150,000 a year.
The Conservative leader became a father again earlier this year when his fiancee Carrie Symonds gave birth to a son Wilfred.
But an ally of Mr Johson told the Times that, like other prime ministers before him, he was “very, very badly served”.
They said: “He doesn't have a housekeeper, he has a single cleaner and they're worried about being able to afford a nanny. He's stuck in the flat and Downing Street is not a nice place to live.
"It's not like the Élysée or the White House where you can get away from it all because they're so big. Even if he or Carrie want to go into the rose garden they have to go through the office."
Mr Johnson was also said to be financially supporting, to differing degrees, four of his six children.
As a highly paid columnist for the Daily Telegraph newspaper, speaker and backbench Tory MP, Mr Johson was reported to earn more than £350,000 a year.
His new salary of around £150,000 is a significant cut to do the job he has dreamed of since he was a child.
Conservative MPs are also understood to be surprised at the prime minister’s appearance, after he lost a significant amount of weight in recent weeks.
Mr Johnson has spoken publicly about being overweight as he urged Britons to slim down before a possible second wave of coronavirus this year.
Tory MPs are also concerned about the toll the coronavirus crisis is taking on the prime minister, who was intensive care himself with the disease barely six months ago.