Where can I buy cornmeal in the UK?

If you are in London, Partridge's in Kensington has the Quaker brand cornmeal.  I bought some myself, I think it was about £2.50. 

I was quite shocked that they didn't have polenta in the international aisle or maize meal with the Indian foods at the major supermarkets here.  

Sometimes I find stuff in the most random locations or have to ask. Cans of tuna above the freezer section??