A recent study in Oxford¢¥s Journal for Environmental Law suggests that letting cats roam freely outside can damage biodiversity.

The lawyers behind this article say that if the owner of a cat lets it stay outside knowing that it can damage biodiversity, it can be considered breaking a law.

Outdoor cats in the UK are estimated to kill tens of millions of birds a year. The most commonly killed species are house sparrows, blue tits, blackbirds and starlings.

An EU spokesperson said that the European Commission supports free movement rights, including movement of cats.