Larry has observed half a dozen prime ministers arrive and depart, welcomed world leaders and princes at the famous black door of No 10, and is shortly set to become the longest continuous resident since historical figures.
While the landscape of British politics has changed significantly over the past 15 years, the feline has remained a reassuring steady presence. His lasting appeal - the kind that many leaders would desire - is now featured in a new documentary series exploring the country's affection for cats.
"Larry is definitely the person to encounter at Downing Street," commented one political insider, adding that he "has the freedom of the residence."
The tabby, whose formal title is Head Cat of the Government at 10 Downing Street, was adopted from an rescue center to address a rodent problem. His journey from homeless cat in south London to government resident represents a true rags to riches story that surpasses many official life stories.
When tensions ran high during the coalition government, former leader the ex-PM was eager to dispel any rumors of animosity between him and the nation's new favorite cat. "This story is I don't love Larry - I certainly do," he declared during one government meeting.
Now a more established figure, Larry appears completely accustomed to the spotlight. Often seen on live television lingering patiently by the front door, his calm demeanor in front of cameras has become rather troublesome for the Downing Street groundskeeper - Larry frequently goes to the front flower patch to relieve himself.
His government description describes the 18-year-old cat as passing his days welcoming guests, inspecting security measures, and evaluating antique furniture for napping quality. His regular responsibilities include considering answers to the rodent occupancy in the house.
While Larry is the initial to hold this particular position, cats have been welcomed in the corridors of power for at least a hundred years. "Stability is an vital part of the cat's attraction," explained one expert who has researched people-pet connections.
The cat possesses an acute sense of diplomatic timing. "As soon as moment something happens on the street, especially an formal visit, like routine, he'll be outside the main," remarked a Downing Street source. "He adores the attention."
Former US President Barack Obama and Ukrainian President Volodymyr Zelenskyy are among the world figures he has impressed. However, not officials were equally enamored.
"The former PM famously disliked him because she was a dog person," explained one photographer who has witnessed several MPs attempting, and unsuccessfully, to stroke the cat.
When not treading the pavements, Larry's regular sleeping places include the printer and desk organizers, but his preferred spots are on the window sills on both side of the front door.
The cat's popularity with the public remains undeniable. There are various online accounts dedicated to the nation's chief mouser, including one with over 868,000 fans. He also receives letters, toys, and snacks from across the globe and has recently been included in a book about political pets.
As top feline, Larry inevitably gets his share of criticism. One government commentator recently described him as "excessively overweight and too lazy to really do his duties," claiming him of being "support reliant."
In reply, insiders near to Larry have released a stinging rebuke. They clarify that he is not government paid for, with Number 10 staff voluntarily covering his expenses.