As Chancellor of the Exchequer he may be the holder of one of the oldest and highest offices of state, but that has not saved Philip Hammond from being humiliated by his neighbour.
Or to be more precise, his neighbour’s cat.
While relations between Mr Hammond and his Prime Minister appear at the moment to be good, the same cannot be said for Rex, the Chancellor’s welsh terrier, and Oscar, his wire haired dachshund, and Larry, the resident cat at No 10.
It seems that Larry has taken a dislike to the two dogs, so much so that Mr Hammond has confessed to friends that he has been forced to keep them inside the flat for their own safety since he moved in with his wife Susan a fortnight ago.
To ensure peace is maintained at the heart of government Mr Hammond has reluctantly had to ensure Rex and Oscar are no longer able to wander around the Number 10 offices below.
The dogs are not free to roam around the house. The cat is all over the place, said one friend. Larry fights, he is pretty feisty. The dachshund is pretty small and I am not at all sure if it really came to a punch up who would come off best.
On hearing that Mr Hammond kept dogs Downing St officials initially feared that it would be Larry who would have to be kept inside for his own safety.
However, he was clearly prepared to defend his territory, which so happens to be the most famous political address in the world.
Larry has previously been better known for his violent spats with Palmerston, the Foreign Office cat – frequently caught on camera by the press photographers on duty outside No 10 – than for his success in catching mice.
He has been photographed numerous times chasing Palmerston around Downing Street, and the two have had to be separated by Number 10 security.
The Hammonds’ dogs are not the first to live in Downing Street. In 2013 George Osborne announced he had purchased Bichon Frise puppy Lola.
Friends of Mr Osborne confirmed that he had also had to keep control of Lola to avoid fights with Larry.
One said: “Lola lived upstairs in the kitchen of the flat and was taken down to the garden and park on a lead for walks. Larry ruled the roost downstairs, mainly asleep on the radiators in the Number 10 and Number 11 hallways.
“He used to come into George’s study and sleep in there quite a bit as it was quieter than No 10.”
The arrival in Downing St of the Hammonds – who have three children – from their home in nearby Chelsea was delayed while Mr Osborne and his wife Frances moved their possessions out of the flat.
Some repair work was also carried out after the roof in Number 10 sprang a leak.
One source close to Mr Hammond said he was “not particularly” a cat person and would not choose to have one himself.
Mrs May – who lives with her husband Philip – appears to share the same sentiment, saying recently that she has “always had dogs” when asked about her relationship with Larry.
In contrast to the number of pets in Downing St, the Parliamentary authorities at the House of Commons authorities have warned staff that pets are not allowed on the premises.
As a result there is now an attempt to persuade Gavin Williamson, the Government Chief Whip, to remove his pet spider Cronus, which he keeps on his desk in the House of Commons.
Mr Williamson has refused to budge, saying when the mouse problem has been sorted out, then he will consider removing his eight-legged friend. Mr Osborne tweeted a photo of Cronus this week.
Sir Alan Duncan,a foreign office minister, agrees with Mr Williamson, saying his dog Noodle was indignant about the ban and said he might bring his pet into the Foreign Office as an act of defiance.
MPs and staff have complained the pet ban is unfair and counterproductive, given the number of mice stalking the corridors of power.
Stella Creasy, the Labour MP for Walthamstow, tweeted: This is so UNFAIR. When does Parliament get its own cats? We’ve got loads of mice (and some rats!) after all!
Penny Mordaunt MP, a former Tory defence minister, was so aggrieved by the situation that she brought in her pedigree cat, Titania, in the hope she would kill some mice.
Responding to a poster which offered advice on how to help end the mouse infestation, one rebellious staff member responded with some defiant graffiti: GET US A CAT.