The two cats are know to be hostile to one another. And have fights. However, Larry and Palmerstons most recent fight are said to be the ''most brutal yet''.
The two cats clashed at Downing Street. Larry is the Chief Mouser for Downing Street. Whereas, Palmerston is the Chief Mouser for the Foreign Office.
One of the employees at Number 10 had to break the two cats up. He said:
"I went and broke them up, and as I broke them up I got scratched on the leg. I was wearing long trousers but the claws went through to my skin.''
Larry has had to have vet treatment for the incident on his paws.