Judgment

HEGDE, J.:- In these appeals by special leave, a common question of law arises for decision and that question relates to the scope and effect of the Central Sales Tax (Amendment) Act, 1969.

2. The amendment in question came to be enacted under the following circumstances. The High Court of Mysore in Yadalam Lakshminarasimhiah Setty and Sons v. State of Mysore, (1962) 13 STC 583 (Mys), held that under S. 8 (2) of the Central Sales-tax Act, 1956, prior to its amendment by Act 31 of 1958 a "sale" in the course of inter-State trade or commerce is to be taxed at the same rate and in the same manner as it would have been taxed, under the appropriate State law, if it had been an intra-State transaction, but without taking into consideration the minimum turnover fixed by the State law for the purpose of determining the liability of the "dealer" to be assessed under the State sales tax law. It further held that the words "same manner" in Section 8 (2) relate to the calculation of the tax and not refer to the procedure to be adopted while assessing the "dealer."

3. This decision was affirmed by the SC in State of Mysore v Yadalam Lakshminarasimhiah Setty and Sons, 16 STC 231. Thereafter on June 9, 1969, the President of India promulgated the Central Sales Tax (Amendment) Ordinance 1969, with the object of superseding the effect of the decision in Yaddalam Lakshminarasimhiah Setty s case and to bring to tax sales effected by every dealer in the course of inter State trade or commerce notwithstanding the fact that no tax could have been levied under the sales tax law of the appropriate State if that sale had been an intra-State sale. That provision was given retrospective effect but it was provided in S. 10 (1) of the Amendment Act:

"Where any sale of goods in the course of inter-State trade or commerce has been effected during the period between the 10th day of November, 1964 and the 9th day of June 1969, and the dealer effecting such sale has not collected any tax under the principal Act on the ground that no such tax could have been levied or collected in respect of such sale or any portion of the turnover relating to such sale and no such tax could have been levied or collected if the amendments made in the principal Act by this Act had not been made, then, notwithstanding anything contained in Section 9 or the said amendments, the dealer shall not be liable to pay any tax under the principal Act, as amended by this Act, in respect of such sale or such part of the turnover relating to such sale."

Sub-section (2) of S. 10 provided:

"For the purposes of sub-sec. (1) the burden of proving that no tax was collected under the principal Act in respect of any sale referred to in sub-section (1) or in respect of any portion of the turnover relating to such sale shall be on the dealer effecting such sale."

4. That Ordinance was replaced by the Central Sales Tax (Amendment) Act, 1969. After the amendment came into force several Sales Tax Officers who had earlier assessed the assessees in accordance with the decision in Yadalam Lakshminarasimhiah Setty s case 16 STC 231 issued notices to those assessees proposing to rectify their assessments on the ground that the earlier assessments suffered from mistakes apparent on the record. The respondents in these appeals resisted those notices on the ground that they had no competence to reopen the assessment. The Sales-tax Officers rejected that contention. Thereafter the respondents in these appeals challenged the orders made by the Sales-tax Officers before the High Court of Mysore by means of petitions under Art 226 of the Constitution on two grounds viz. (l) that the Sales-tax Officer had no jurisdiction to reopen the assessment as there was no mistake apparent on the record and (2) that the said Officer was in error in coming to the conclusion that the assessee had collected tax on the turnover which was earlier considered as exempted. The High Court accepted the first of the two afore-mentioned