It tends to be small pet shops that sell it rather than large stores or supermarkets. There's a pet shop near me that sells individual tins. Lately I've been buying it from cat shows as they usually have show offers on where you can buy it cheaper. Or you can get it online from MPM products
http://www.mpmproducts.co.uk/Almo nature is an identical food and zooplus sell that - they do a tuna one too.