Writ prohibition and tax estoppel fail where excise proceedings are at notice stage and later-period liability remains open.

Writ prohibition was unavailable at the show-cause stage because the excise authority had jurisdiction to initiate proceedings and the dispute required factual adjudication by the departmental forum. The impugned communication was only an intimation and the notice was only a show-cause notice, so the challenge was premature. Earlier exemption and duty refund did not create estoppel against law or bar inquiry for a later tax period, since each assessment period is a separate unit and no binding adjudication for that period was shown. The departmental proceedings were therefore permitted to continue in accordance with law.

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Issues: (i) Whether writ jurisdiction could be invoked to prohibit further excise proceedings at the stage of a communication and show cause notice. (ii) Whether the Revenue was barred from initiating proceedings for a later period because exemption had earlier been granted and duty refunded.

Issue (i): Whether writ jurisdiction could be invoked to prohibit further excise proceedings at the stage of a communication and show cause notice.

Analysis: The impugned communication dated 4-12-1980 was only an intimation that the goods would be treated as liable to duty and could not be treated as a demand in law. The notice dated 9-12-1980 was only a show cause notice. A writ of prohibition at the threshold lies only where there is a patent and total want of jurisdiction. The authority had undoubted power to initiate proceedings for recovery of short-levied duty under the statutory scheme, and the dispute involved factual questions requiring adjudication by the departmental authorities.

Conclusion: The challenge to the proceedings at the show cause stage was premature and was not maintainable; the appellants were not entitled to prohibition.

Issue (ii): Whether the Revenue was barred from initiating proceedings for a later period because exemption had earlier been granted and duty refunded.

Analysis: The earlier grant of exemption did not create an estoppel against law. In tax matters, each period of assessment is a separate unit, and an earlier departmental stand does not prevent the Revenue from examining the liability for a subsequent period. The nature of the product and the character of the activity for the relevant period required factual inquiry, and no binding adjudication for that period had been shown.

Conclusion: The Revenue was not precluded from reopening the issue for the relevant period, and the earlier exemption/refund did not bar the proceedings.

Final Conclusion: The writ appeals failed, and the departmental proceedings were permitted to continue for adjudication in accordance with law.

Ratio Decidendi: A writ of prohibition cannot be used to stop excise proceedings where the authority has jurisdiction and the dispute turns on factual adjudication, and in tax matters an earlier exemption or refund does not operate as estoppel or res judicata against inquiry for a different period.

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