Promissory estoppel against Government agencies was decided in Pournami Oil Mills v. State of Kerala, AIR 1987 SC 590. II in response to an order-exemption made by the Government and in consideration of the concession made available therein the promoters of any small scale concern set up their industries within the State, they would certainly be entitled to plead the rule of estoppel in their favour when the State purports to act differently withdrew the exemption-concession.