JAGANMOHAN REEDY, C.J.

In this batch of writ petitions, the validity of item 6 of Schedule III to the Andhra Pradesh General Sales Tax Act, 1957 (hereinafter called "the State Act") is challenged on the grounds : (1) that it designates two stages of taxation in respect of groundnuts, which being oil-seeds are "declared goods" within the meaning of section 14 of the Central Sales Tax Act, 1956 (hereinafter called "the Central Act") and is therefore contrary to the provisions of section 6 of the State Act; (2) that the classification of dealers as millers and other dealers is discriminatory and unreasonable and as such violative of Article 14 of the Constitution; and (3) that the levy of tax on turnover of groundnuts in that entry exceeds the maximum fixed under section 15(a) of the Central Act. Inasmuch as in all these writ petitions a general question of law alone arises, it is unnecessary to set out the facts in each case, except in one, i.e., W.P. 362 of 1968, as typifying the points that arise for determination in all these cases.

The petitioner-firm (hereinafter called the assessee) is a registered dealer under the Central and State Acts dealing in groundnuts, on the purchases of which it is being subjected to tax under item 6 of Schedule III of the State Act, and on which it is paying tax. For the year 1965-66, the assessee was assessed to a tax of Rs. 4,083.00 on its purchases of groundnut, by the order dated 2nd September, 1966. The assessment for 1966-67 is not yet completed, but the assessee paid the tax in advance on a purchase turnover of Rs. 2,83,247.37 at 3 per cent. For the year 1967-68 the assessee has been submitting monthly returns and has also paid the tax up to November, 1967. It is the case of the assessee that it was advised that the levy of tax on groundnuts is illegal and unconstitutional.

It is contended that inasmuch as Article 286(3) of the Constitution, added by the Constitution (Sixth Amendment) Act, authorises Parliament by law to impose such restrictions and conditions in regard to the system of levy, rates and other incidents of the tax as it may by law specify, on a law made by a State imposing or authorising the imposition of a tax on the sale or purchase of goods declared by the Parliament by law to be of special importance in inter-State trade or commerce, and that since Parliament, in exercise of that power, has passed the Central Act, section 14 of which lists the goods which are of special importance in inter-State trade or commerce- hence forward termed as declared goods of which item 6 of Schedule III of the State Act, namely, oil-seeds, is one, the levy and imposition of tax on which is the subject-matter of these writ petitions - and section 15 imposes restrictions on the sales tax law of a State in so far as it imposes or authorises the imposition of tax on the sale or purchase of declared goods inside the State by prescribing that it shall not exceed 3 per cent of the sale or purchase price thereof and that such tax shall not be levied at more than one stage, any imposition which exceeds the maximum prescribed under section 15 is invalid.

Sri Anantha Babu contends that inasmuch as section 6 of the State Act provides that notwithstanding anything contained in, section 5, the sales or purchases of declared goods by a dealer shall be liable to tax at the rate and only at the point of sale or purchase specified against each in the Third Schedule on his turnover of such sales or purchases for each year, irrespective of the quantum of his turnover in such goods, and the tax shall be assessed, levied and collected in such manner as may be prescribed, and as item 6 in the Third Schedule, i.e., groundnuts, prescribes the levy when purchased by a miller other than a decorticating miller in the State at the point of purchase by such miller and in all other cases at the point of purchase by the last dealer who buys in the State, it violates the provisions of section 15(a) of the Central