Statutory tariff concession can be withdrawn under the same power that granted it; promissory estoppel cannot block amendment.

A statutory electricity tariff concession granted under an amendmentable schedule remained a defeasible benefit, not an indefeasible right. Because the State acted within the same statutory framework that created the concession, promissory estoppel could not be used to compel its continuance after the tariff schedule was amended. The Court also rejected the challenge based on the units' profit position and the State's policy choice, treating the grant and withdrawal of tariff concessions as matters within the State's lawful domain absent legal infirmity. The amended tariff and demand for normal rates were therefore upheld.

---

---

Issues: (i) Whether the appellants could invoke promissory estoppel to compel continuance of concessional electricity tariff after amendment of the tariff schedule; (ii) Whether the challenge to withdrawal of concessional tariff on the ground that the units had not made profits and on the basis of the State's policy choice could succeed.

Issue (i): Whether the appellants could invoke promissory estoppel to compel continuance of concessional electricity tariff after amendment of the tariff schedule.

Analysis: The concessional tariff was originally granted under a statutory regime and was later modified by amendment to the Schedule under the power conferred by the statute. The benefit was in the nature of a concession and not an indefeasible right. Once the State acted within the statutory framework to alter the concession, the doctrine of promissory estoppel could not be used to prevent the statutory withdrawal or modification of the benefit. A concession granted by law remains liable to be altered or withdrawn in exercise of the same power under which it was granted.

Conclusion: The plea of promissory estoppel failed, and the appellants had no enforceable right to insist on continuation of the concessional tariff.

Issue (ii): Whether the challenge to withdrawal of concessional tariff on the ground that the units had not made profits and on the basis of the State's policy choice could succeed.

Analysis: The Court found no merit in the contention that the profit or loss position should be assessed differently so as to keep the concession alive. The State's method of applying the profit-based condition to the industry was treated as a policy matter within its domain. The later reversal of the tariff position did not invalidate the earlier amendment, because the determination of tariff concessions and their withdrawal lay with the State and not with the Court, absent legal infirmity.

Conclusion: The ancillary challenges to the withdrawal of concessional tariff were rejected.

Final Conclusion: The statutory amendment and the consequent demand for tariff at normal rates were upheld, and the appeals failed in their entirety.

Ratio Decidendi: A statutory concession in tariff is a defeasible benefit that can be withdrawn or modified under the very power by which it was granted, and promissory estoppel cannot be invoked to defeat such statutory action.

---