This is the ingredient list for the cheap ones in the Bird's Eye range that I tend to buy:
Alaska Pollock (Fish) (58%), Breadcrumb Coating*, Sunflower Oil, *Breadcrumb Coating (Wheat Flour, Water, Potato Starch, Salt, Paprika, Yeast, Turmeric)
And this is for the super cheap (69p for a pack of 10) Morrison's Saver ones (they don't have a great texture I think because it is minced offcuts, I prefer the Bird's Eye ones):
Minced Alaska Pollock (Fish) (58%), Fortified Wheat Flour (Wheat Flour, Iron, Thiamin, Nicotinic Acid, Calcium Carbonate), Sunflower Oil, Water, Yeast, Salt, Colours (Paprika Extract, Curcumin), Turmeric