As per case facts, the State of Maharashtra had granted exemptions from electricity duty to captive power generators, which were later modified or withdrawn by new notifications. These actions were ... challenged, leading to the High Court striking down the withdrawal notifications as arbitrary and discriminatory. The State appealed, arguing its power to withdraw exemptions based on budgetary deficit and public interest. The question arose whether the State, after granting a concession, could withdraw or modify it without being considered arbitrary, and if the principles of promissory estoppel or legitimate expectation applied, particularly regarding the need for reasonable notice for industries that had made significant investments. Finally, the Supreme Court upheld the State's statutory power to withdraw or modify exemptions for public interest and fiscal stability, ruling that promissory estoppel and legitimate expectation did not bar such actions. However, the Court found the sudden withdrawal unfair, stating that fair play demanded a reasonable transitional period. It thus ruled that the impugned notifications would take effect only after a one-year notice period from their respective dates, allowing industries to adjust.