...look at the judgments of Lord Denning and Scarman, L.J, it is apparent that they did not base their decision on any distinctive feature of proprietary estoppel but proceeded on the assumption that there...sold by the appellant from payment of Sales Tax for a period of three years from July 2, 1970. This plea based on the doctrine of promissory estoppel was, however, rejected by the Division Bench of the...reliance on it, altered its position and the State Government was, therefore, bound, on the principle of promissory estoppel, to honour the assurance and exempt the appellant from Sales Tax for a period of...