Well I couldnt say for certain about London, but I would say yes as they are all over the country including the south east.
Most towns....and villages have them.
Loads. I am near Pollards Hill, the place God created last in a bad mood, and there are 3 within 2 miles. They do BOGOFs and the best microwaveable mash available anywhere.
Are you looking for a Co-op food store or one of their department stores?
For food stores, go to http://www.yell.com
Enter 'grocers' under Product/Service, 'co-op' under Name and 'London' as the location. You'll get 50 'hits'.
Replacing 'grocers' with 'department stores' yields just one result:
168-176, Eltham High St, Eltham, London, SE9 1BJ
Tel: 020 8850 2631