I think you have to read the small print at certain places but I've seen remnants of beach fires at Cooden Beach and Worthing. Cooden has the benifit of being mire isolated and you can park the bus right next to you.
Next time I'm down there I'll take a look at the signs. I know they don't allow campers there over night. BOO!!!
Cheers guys! I just remembered we once stayed on a campsite just east of Rock in Cornwall and had a fire on the beach on the estuary.
also make sure the beach isn't in a wildlife / protected area I know you can have them on sandsend beach near whitby cos i've seen them there. bek