The one-year-old brown and white male was discovered inside a cubicle by a diner at the Swiss Cottage restaurant in St Peter's Street.
He has now been taken to a Cats Protection shelter in Dalbury Lees where staff are hoping to re-home him.Flush was shaking and panting when he was found but has since recovered
Manager Helen Wood said the cat had been "slightly bemused" by the ordeal but had since recovered.
Flush is one of 199 cats at the shelter, which is being extended to cope with a sharp rise in abandoned cats over the past three years.
Ms Wood said: "He is a friendly, sociable cat with beautiful eyes.
"Hopefully someone will now come forward to offer him a new home."
Source: BBC news