Divan, C.J.

1. The point arising for determination in all these cases is common and that is why we are disposing of these matters by a common judgment.

2. The petitions raise interesting questions regarding the applicability of the Central Sales Tax Act as amended by Central Act 103 of 1976. By that Amendment Act of 1976, Section 5 of the Central Sales Tax. Act was amended with effect from 1st April, 1976, and by this amendment, a new sub-section, Sub-section (3), was inserted. The Central Sales Tax (Amendment) Act, 1976, was brought on the statute book on 9th September, 1976 ; but the amendment was given retrospective effect from 1st April, 1976. The Andhra Pradesh General Sales Tax Act was amended with effect from 1st September, 1976, by Andhra Pradesh Act 49 of 1976 and, by this amendment, items 19 and 20 were added to the Second Schedule to the Andhra Pradesh General Sales Tax Act. The Second Schedule deals with goods in respect of which only a single point sales tax is leviable under Section 5(2)(b) of the Andhra Pradesh General Sales Tax Act. Section 5 deals with levy of tax on sales or purchases of goods and under Section 5(1) every dealer (other than a casual trader and an agent of a non-resident dealer) whose total turnover for a year is not less than Rs. 25,000 and every agent of a non-resident dealer, whatever be his turnover for the year, shall pay a tax for each year, at the rate of four paise on every rupee of his turnover. Every casual trader shall pay a tax at the rate of four paise on every rupee of his turnover. Under Section 5(2)(b), notwithstanding anything contained in Sub-section (1), the tax under the Act shall be levied in the case of the goods mentioned in the Second Schedule, at the rates and only at the point of purchase specified as applicable thereto, effected in the State by the dealer purchasing them, on- his turnover of purchase in each year relating to such goods irrespective of the quantum of turnover. Item 19 of the Second Schedule, which was inserted with effect from 9th September, 1976, is in these terms :

3. In this connection, it is important to note that, under Article 286(1) of the Constitution, no law of a State shall impose, or authorise the imposition of a tax on the sale or purchase of goods where such sale or purchase takes place (a) outside the State ; or (b) in the course of the import of the goods into, or export of the goods out of, the territory of India. After the Sixth Amendment of the Constitution in 1956, by virtue of Clause (2) of Article 286, Parliament may by law formulate principles for determining when a sale or purchase of goods takes place in any of the ways mentioned in Clause (1). By virtue of the powers thus conferred on Parliament by Clause (2) of Article 286 of the Constitution, Section 5 of the Central Sales Tax Act, which was enacted in 1956, provides as to when a sale or purchase of goods can be said to take place in the course of import or export of the goods. We are concerned, so far as the present judgment is concerned, with Sub-sections (1) and (3) of Section 5 of the Central Sales Tax Act. Sub-section (1) of Section 5 of the Central Sales Tax Act provides that a sale or purchase of goods shall be deemed to take place in the course of the export of the goods out of the territory of India only if the sale or purchase either occasions such export or is effected by a transfer of documents of title to the goods after the goods have crossed the customs frontiers of India. As already pointed out, Sub-section (3) of Section 5 was inserted by the Central Sales Tax (Amendment) Act (103 of 1976) with effect from 1st April, 1976, and Sub-section (3) is in these terms :

Notwithstanding anything contained in Sub-section (1), the last sale or purchase of any goods preceding the sale or purchase occasioning the export of those goods out of the territory of India shall also be deemed to be in the course of such export, if such last sale or purchase took place after, and was for the purpose of complying with, the agreement or order for or in relation to such export.

4. A lot of controversy has been going on in the law courts regarding the meaning of the words "sale or purchase which occasions export of the goods". But after the decision of the Supreme Court in the Serajuddin's case [1975] 36 S.T.C. 136 (S.C.) it became clear that it was only the last sale effected by the actual exporter, who exported the goods out of the territory of India that was covered by Section 5(1). In view of this decision of the Supreme Court in the Serajuddin's case [1975] 36 S.T.C. 136 (S.C.), the Parliament, in order to give relief to those who entered into the penultimate transactions with the actual exporters of goods, enacted the Central Sales Tax (Amendment) Act (103 of 1976) and by virtue of Sub-section (3) of Section 5, relief is sought to be given not only to the actual exporter but also to the last dealer whose sale or purchase of any goods is the immediate sale or purchase preceding the sale or purchase occasioning the export of those goods out of the territory of India. So, over and above the transaction of the actual exporter out of India, even the transaction of a person who sells these goods to that exporter is now brought within the meaning of the words "sale or purchase in the course of export of the goods out of the territory of India".

5. At this stage, we may point out that, under Section 38 of the Andhra Pradesh General Sales Tax Act, nothing contained in the Act is to be deemed to impose or authorise the imposition of a tax on the sale or purchase of any goods, where such sale or purchase takes place (i) outside the State; or (ii) in the course of the import of the goods into, or export of the goods out of, the territories of India ; or (iii) in the course of inter-State trade or commerce. By virtue of the explanation to Section 38, the provisions of Chapter II of the Central Sales Tax Act, 1956, shall apply for the purpose of determining when a sale or purchase takes place in the course of inter-State trade or commerce or outside a State or in the course of import or export. It is clear that Section 38 of the Andhra Pradesh General Sales Tax Act merely gives effect to the provisions of Article 286 of the Constitution and reiterates what has been laid down in Article 286.

6. Mr. P. A. Chowdhary appearing for the petitioners in W. P Nos. 548 and 550 of 1977 has contended that Andhra Pradesh Act 49 of 1976 is invalid because of the enactment of central act 103 of 1976. The argument runs in this manner : Before the Central enactment was made, the State, law was competent because it was in conformity with Section 5(1) and (2) of the Central Sales Tax Act. But after the insertion of Section 5(3) in the Central Sales Tax Act with effect from 1st April, 1976, i.e., with effect from a date prior to the coming into force of Andhra Pradesh Act 49 of 1976, the State law cannot be regarded as valid so far as the insertion of items 19 and 20 in the Second Schedule to the Andhra Pradesh General Sales Tax Act is concerned, because the Andhra Pradesh General Sales Tax Act, as amended by Andhra Pradesh Act 49 of 1976 is in conflict with the Central law and cannot be deemed to have been saved by Section 38 of the Andhra Pradesh General Sales Tax Act. As regards the provisions of Section 38, Mr. Chowdhary argued that Section 38 should be understood as referring to the provisions of Chapter II of the Central Sales Tax Act, 1956, as they were in existence at the time when Section 38 was enacted in 1957. According to Mr. Chowdhary, only if Section 38 is so read, can any meaning be given to the provisions of law enacted by the State Legislature. The State Legislature, according to him, while enacting this law, must be deemed to have applied its mind and must be deemed to have laid down a policy or principle after a consideration of what the standard of policy or principle should be. He contended that the validity of Andhra Pradesh Act 49 of 1976 must be decided with reference to the provisions of the law on the day when the enactment has come to be made. From these premises, Mr. Chowdhary contends that Section 38 exempts only sales or purchases covered by Section 5(1) and (2) of the Central Sales Tax Act and not those covered by Section 5(3) which was brought on the statute book nearly 19 years after Section 38 was enacted. It was contended that the State Legislature cannot be imputed with the intention to abdicate its legislative power in favour of the Central Legislature. Mr. Chowdhary relied upon the decision of the Supreme Court in B. Shama Rao v. Union Territory Of Pondicherry., Pondicherry A.I.R. 1967 S.C. 1480, and contended that it was not open to the State Legislature to adopt future law. He, therefore, submitted that central act 103 of 1976 cannot be said to be in the contemplation of the State Legislature when it enacted Section 38 of the Andhra Pradesh General Sales Tax Act and he said affirmatively that Section 38 must be taken to comprehend only Chapter II of the Central Sales Tax Act, 1956, as it existed on the day when the Andhra Pradesh General Sales Tax Act was enacted in 1957. He contended that the State law, as amended by Andhra Pradesh Act 49 of 1976 cannot be regarded as valid, because items 19 and 20 added to the Second Schedule to the Andhra Pradesh General Sales Tax Act are in conflict with the Central law and cannot be deemed to have been validly inserted.

7. We are afraid the decision in B. Shama Rao v. Union Territory Of Pondicherry., Pondicherry, cannot help the petitioner. Unlike, as was held by the Supreme Court in the Shama Rao's case A.I.R. 1967 S.C. 1480, it cannot be said that the Andhra Pradesh State Legislature, in enacting Section 38, had totally abdicated its legislative function in the matter of sales tax legislation and surrendered it in favour of the Central Parliament. Even at the time when Section 38 was enacted by the Andhra Pradesh State Legislature in 1957, Article 286 of the Constitution provided the overriding framework in the context of which the State Legislature could enact any legislation regarding sales tax and by virtue of Article 286, as amended after the Sixth Amendment Act, 1956, it was for the Parliament to formulate by law principles for determining when a sale or purchase of goods takes place either outside the State or in the course of the import of the goods into or export of the goods outside the territory of India. Even if Section 38 along with its explanation was not part of the Andhra Pradesh General Sales Tax Act, the same result would have followed by virtue of the provisions of Article 286(2) of the Constitution. As we have pointed out earlier, Section 38 merely gives recognition to the principles laid down in Article 286(2) and, therefore, there was no question of the Andhra Pradesh State Legislature abdicating its functions or doing something which it was not competent to do or enacting for the future. By virtue of Article 286(2), it is in the light of the principles formulated by the Parliament for determining when a sale or purchase of the goods takes place in the course of export of the goods out of the territory of India that the State Sales Tax Acts have to be interpreted and the Shama Rao's case A.I.R. 1967 S.C. 1480 has no application to the facts of the case before us.

8. In this connection, we may point out that, in Gwalior Rayon Silk Mfg. (Wvg.) Co. Ltd. v. Assistant Commissioner of Sales Tax [1974] 33 S.T.C. 219 (S.C.), the Supreme Court held that Parliament, by enacting Section 8(2) (b) of the Central Sales Tax Act effectuated its legislative policy, according to which the rate of Central sales tax should in certain contingencies be not less than the rate of local sales tax in the appropriate State. Such a law cannot be said to be suffering from the vice of excessive delegation of legislative function. On the contrary, it carries out the objective of the legislature, viz., to prevent evasion of payment of Central sales tax and plug the possible loopholes. Thus, on the facts of the case before us, it is obvious, as is clear from this decision of the Supreme Court, that the question of the Andhra Pradesh State Legislature delegating its legislative function to the Central Parliament never arose, because the Andhra Pradesh State Legislature merely gave effect to the provisions of Article 286(2) of the Constitution.

9. In this connection, we may also point out that, in Sundararamier & Co. v. State of Andhra Pradesh [1958] 9 S.T.C. 298 (S.C.), in the context of Article 286, the provisions of Section 22 of the Madras General Sales Tax Act were considered by the Supreme Court. Section 22 of the Madras Act was in terms identical with Section 38 of the Andhra Pradesh General Sales Tax Act. Venkatarama Aiyar, J., speaking for the majority, has discussed the question from page 307 of the Reports onwards. Quoting from Willoughby on the Constitution of the United States, Vol. I, it was pointed out:

The validity of a statute is to be tested by the constitutional power of a legislature at the time of its enactment by that legislature, and, if thus tested it is beyond the legislative power, it is not rendered valid, without re-enactment, if later, by constitutional amendment, the necessary legislative power is granted.

However, it has been held that where an Act is within the general legislative power of the enacting body, but is rendered unconstitutional by reason of some adventitious circumstance, as for example, when a State Legislature is prevented from regulating a matter by reason of the fact that the Federal Congress has already legislated upon that matter, or by reason of its silence is to be construed as indicating that there should be no regulation, the Act does not need to be re-enacted in order to be enforced, if this cause of its unconstitutionally is removed.

10. At page 336, summing up the result of the authorities, Venkatarama Aiyar, J., observed :

Where an enactment is unconstitutional in part but valid as to the rest, assuming of course that the two portions are severable, it cannot be held to have been wiped out of the statute book as it admittedly must remain there for the purpose of enforcement of the valid portion thereof, and being on the statute book, even that portion which is unenforceable on the ground that it is unconstitutional will operate proprio vigore when the Constitutional bar is removed, and there is no need for a fresh legislation to give effect thereto. On this view, the contention of the petitioners with reference to the explanation in Section 22 of the Madras Act must fail. That explanation operates, as already stated, on two classes of transactions. It renders taxation of sales in which the property in the goods passes in Madras but delivery takes place outside Madras illegal on the ground that they are outside sales falling within Article 286(1)(a). It also authorises the imposition of tax on the sales in which the property in the goods passes outside Madras but goods are delivered for consumption within Madras. It is valid in so far as it prohibits tax on outside sales, but invalid in so far as sales in which goods are delivered inside the State are concerned, because such sales are hit by Article 286(2).

11. Thus, the provisions of Section 38 and the explanation to Section 38 have to be read in the light of Article 286(2) of the Constitution. In this connection, we may also point out that, in I. C. Corporation (P.) Ltd. v. Commercial Tax Officer [1975] 35 S.T.C. 1 (S.C.), Alagiriswami, J., speaking for the Supreme Court, pointed out how the question of interaction between the Central Sales Tax Act and the State Sales Tax Act has to be considered. The question in J. C. Corporation (P.) Ltd. v. Commercial Tax Officer [1975] 35 S.T.C. 1 (S.C.) was the same as in the earlier decision in State of Tamil Nadu v. Sitalakshmi Mills Ltd. [1974] 33 S.T.C. 200 (S.C.) The argument similar to the argument advanced by Mr. Chowdhary regarding what the Andhra Pradesh State Legislature had in mind in 1957 while enacting Section 38, also appears to have been advanced before the Supreme Court and at page 7 of the Reports, Alagiriswami, J., observed as follows:

It is next contended that as section 8(2)(a) states that the tax payable shall be calculated at the rate applicable to the sale or purchase of such goods inside the appropriate State, it is the rate that was prevalent when section 8(2)(a) was enacted that would be applicable and not any subsequent variations in this rate of tax. If this argument is accepted no question of unconstitutional delegation of the Parliament's legislative powers in favour of the State Legislatures would arise at all. It would be remembered that the ground for attacking the constitutionality of section 8(2)(a) is that Parliament if it is deemed to have permitted the application of rate of sales tax enacted by a State Legislature in respect of intra-State sales to inter-State sales also that would be impermissible delegation by Parliament of its legislative powers. We have already dealt with that question. All that is necessary now to add is that the rate applicable merely means the rate applicable at the relevant point of time and not the rate applicable when section 8(2)(a) was enacted. The whole scheme of the Central Sales Tax Act is to adopt the machinery of the law relating to Sales Tax Acts of the various States, in cases where those States happen to be the appropriate States as also the rates prescribed by those Acts.... Though the tax is levied and collected by the Government of India it is intended for the benefit of and is paid to the State whose officers assess and collect the tax. We are satisfied that the rate applicable is the rate applicable at the relevant point of time. Only that interpretation is consistent with the legislative policy that inter-State trade should not be discriminated against.

12. Under these circumstances, in our opinion, the argument relating to the constitutional validity of Andhra Pradesh Act 49 of 1976 must be rejected. If we had felt any doubt even on prima jade considerations regarding the validity of Andhra Pradesh Act 49 of 1976, we would have referred the question to a larger Bench of Five Judges, because after the 42nd Amendment of the Constitution, it is only a Bench of Five Judges which can declare a State enactment invalid. ,

13. In this connection, it may be pointed out that the effect of Article 286(3) of the Constitution was dealt with by the Supreme Court in Modi Spinning and Weaving Mills Co. Ltd. v. Commissioner of Sales Tax [1965] 16 S.T.C. 310 (S.C.). Article 286(3) provides that any law of a State shall, in so far as it imposes, or authorises the imposition of, a tax on the sale or purchase of goods declared by Parliament by law to be of special importance in inter-State trade or commerce, be subject to such restrictions and conditions in regard to the system of levy, rates and other incidents of the tax as Parliament may by law specify. It was pointed out in that decision that the meaning or the interpretation of Clause (3) of Article 286 of the Constitution of India is not to destroy all charging sections in the Sales Tax Acts of the States which are discrepant with Section 15(a) of the Central Sales Tax Act, 1956, but to modify them in accordance therewith. The law of the State is declared to be subject to the restrictions and conditions contained in the law made by Parliament and the rate in the State Act would pro tanto stand modified. In our opinion, the same principles are to be applied in dealing with the problem before us. All that we have to do is to read the provisions of item 19 read with Section 5(2)(b) of the Andhra Pradesh General Sales Tax Act in the light of and to the extent to which the same are modified by Section 5(3) of the Central Sales Tax Act, when it is contended that the sale or purchase had taken place in the course of export of the goods out of the territory of India. If the first purchase contemplated by item 19 is in connection with the sale which occasions the export within the meaning of Section 5(1) or is the immediately preceding sale or purchase to that occasioning the export of those goods out of the territory of India within the meaning of Section 5(3) of the Central Sales Tax Act, a single point purchase tax cannot be levied by virtue of Section 5(2) (b) of the Andhra Pradesh General Sales Tax Act. The last sale or purchase referred to in Section 5(3) of the Central Sales Tax Act is exempt from the operation of the section, if such last sale or purchase takes place after and was for the purpose of complying with the agreement or order for or in relation to the export of the goods and the sale or purchase must have occasioned such export in the sense as explained by Section 5(1) read with Section 6(3) of the Central Sales Tax Act. As has been pointed out in the counter-affidavit filed on behalf of the respondents in this batch of writ petitions, before exemption can be claimed by virtue of Section 5(3) of the Central Sales Tax Act: (1) there must have been a pre-existing agreement or order to sell the specific goods to a foreign buyer ; (2) the last purchase referred to in Section 5(3) must have taken place after the said agreement with the foreign buyer was entered into ; and (3) the said purchase must have been for the purpose of complying with the said pre-existing agreement or order.

14. Only if these three conditions are satisfied, the exemption covered by Section 5(3) can be availed of by the dealer concerned. We may point out that, in W. P. No. 4090 of 1976, the petitioner has prayed for a writ of prohibition or any other appropriate writ, direction or order commanding the respondents therein to refrain from taxing the petitioner's purchases of prawns, lobsters, frogs and frog legs under the Andhra Pradesh General Sales Tax Act and pass such other orders as may be just and proper. The ultimate question that has to be decided in the course of the assessment is whether the sale or purchase of goods covered by item 19 of the Second Schedule to the Andhra Pradesh General Sales Tax Act after 1st September, 1976, was the last sale or purchase covered by Section 5(3) of the Central Sales Tax Act. In view of Section 38 of the Andhra Pradesh General Sales Tax Act read in the light of Article 286 of the Constitution, it is for the sales tax authorities in the State of Andhra Pradesh to consider whether (1) the sale or purchase occasioned the export of the goods covered by item 19 out of the territory of India ; and (2) whether it is the sale or purchase immediately preceding the sale or purchase which occasioned the export of those goods out of the territory of India. In the light of what we have observed above, it will be for the sales tax authorities to give effect to the provisions of Section 5(3) of the Central Sales Tax Act and give exemption if the requirements of Section 5(3) of the Central Sales Tax Act are satisfied in respect of any particular sales or purchases of the dealers. With these remarks, we must hold that it is not open to us exercising our jurisdiction under Article 226 of the Constitution to issue any specific direction to the sales tax authorities because the required machinery for assessment would be competent and adequate to deal with these questions regarding the satisfaction of the requirements of Section 5(3) of the Central Sales Tax Act, which are essentially questions of fact.

15. In the light of what we have observed above, each of these writ petitions must fail and is dismissed. . The challenge on the ground of constitutional validity cannot be upheld and as regards the directions which the petitioners seek from us as against the sales tax authorities, it is not open to us to give such directions on questions of fact which have to be determined separately in the case of each particular assessee.

16. The result, therefore, is that each of these writ petitions fails and is dismissed. There will be no order as to costs in each of these writ petitions. Advocate's fee Rs. 150 in each of these writ petitions.