The branch says it needs new homes for the adult cats to make space for the kittens it is expecting to receive.
It supports cats and kittens across the city, covering postcodes MK1 to MK19 and MK46.
A spokesperson for the branch told the Citizen: "All rescues get busy this time of year and Cats Protection Milton Keynes is no exception!
"We have 40 cats and kittens in our care, with some cats having spent several months waiting for homes.
"Stormie, for example, has been waiting for over 150 days!
"It's important they get adopted soon so they can get settled with their forever family, and so we can free space to accept other cats desperate to come into our care.
"Mittens and Tinkerbelle could suit most homes, and Mittens may even be able to live with another cat.
"Stormie is looking for a pet-free and child-free peaceful home.
"We know the right family is out there for all of them!"
Applications to adopt the cats must be made through the branch’s website, but first have a look through our gallery to find out a bit more about these lovely cats in search of new owners and a happy home.
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1. Jacob
Seven-month-old Jacob is described as a gorgeous tabby, who enjoys attention and fuss Photo: Fosterers of Cats Protection Milton Keynes
2. Jacob
Jacob is good around children and may be able to live with another cat Photo: Fosterers of Cats Protection Milton Keynes
3. Mittens
Mittens, who is six years old, is described as being very food-driven and will happily lick his bowl clean after meals! Photo: Fosterers of Cats Protection Milton Keynes
4. Mittens
Mittens loves cuddles, sitting on his owner's lap, and is a fan of chasing toys on a stick Photo: Fosterers of Cats Protection Milton Keynes