P.B.GAJENDRAGADKAR, CJI.

(1) THESE writ petitions have been placed for hearing before us in a group, because they raise a common question of law in regard to the validity of the demand for sales tax which has been made against the respective petitioners by the Sales-tax Officers for different areas. The facts in respect of each one of the writ petitions are not the same and the years for which the demand is made are also different; but the pattern of contention is uniform and the arguments urged in each one of them are exactly the same. Broadly stated. the case for the petitioners is that the appropriate authorities purporting to act under the different Sales Tax Acts are attempting to recover from the petitioners sales-tax in respect of transactions to which the petitioners were parties, though the said transactions are not taxable under Art. 286 of the Constitution. Art. 286(1) (a) provides that no law of a Sales shall impose, or authorise the imposition of, a tax on the sale or purchase of goods where such sale or purchase takes place outside the State; and the argument is that the sales in question are all sales which took place outside the State and as such, are entitle