Call the Cats Protection League for advice and assistance.
08702 099 099 (Mon-Fri 9-5)
We had 3 half feral cats at the end of our garden who kept visiting the local tom, so the numbers kept increasing. They spayed them, found homes for the kittens and returned the original 3 cats to us to carry on living at the end of our garden, if we noticed them falling ill the Cats Prtoection League helped to trap them again to get veterinary assistance (we always helped towards costs through donations).