All these writ petitions can be dealt with under a common judgment since they question the validity of section 5B of the Karnataka Sales Tax Act, 1957, introduced by the Amendment Act No. 27 of 1985, with effect from 1st April, 1986.

2. We propose to note the facts in Writ Petitions Nos. 2064 to 2067 of 1988 :

The petitioners are civil engineering contractors engaged in civil construction work in the State of Karnataka. In order to bring the activity of works contract within the purview of power to levy sales tax by the respective State, amendments were introduced extending the definition of "sale" under article 366(29-A) of the Constitution of India. Following the constitutional amendment, the Karnataka Sales Tax Act was amended by the Amendment Act No. 27 of 1985. In pursuance of the amendment, the Karnataka Sales Tax Rules were also amended by the Karnataka Sales Tax (Amendment) Rules, 1986.

As a result of the aforesaid amendments, the activity of the petitioner in the nature of works contract in the State, has been brought within the scope of the Karnataka Sales Tax Act.

The petitioners challenge the constitutionality of the Forty-Sixth amendment, as well as the amendments made to the Karnataka Sales Tax Act. The challenge is in three stages :

(i) the constitutional amendment of procedural and substantive aspect;

(ii) the power of the respective State Legislature to levy and determine tax on works contract without a law made under article 286(3)(b) of the Constitution; and

(iii) the Karnataka Amending Act 27 of 1985 on various grounds of illegality.

By the Forty-sixth Amendment, the definition of "sale" under article 366(29-A) is not an enabling amendment. The power to levy sales tax can only be traced to entry 54 of List II in the State List of the Seventh Schedule. That entry has not been amended by the Forth-sixth amendment. Therefore, merely because clause (29-A) of article 366 of the Constitution was amended, that will not enable the State Government to levy sales tax on works contract. This is because the said article cannot be taken as a source of power, for the simple reason that the connected definitions of "goods" under the Sales of Goods Act, 1930, and "sale" under the Central Sales Tax Act, 1956 have not been amended. Even assuming it is deemed to amend entry 54 of List II, there is no ratification by not less than one half of the State Legislatures as required under article 368 of the Constitution.

The Forty-sixth amendment is also violative of the concept of basic structure doctrine. Though article 286 has been amended, till date the Parliament does not come out with any law fixing the rate of sales tax on works contract. Therefore, the State law will be unconstitutional.

Coming to the definition of "sale" under section 2(1)(t)(ii), it is not only vague and arbitrary but the explanation (3)(c) to section 2(1)(t) is a clear violation of the Sale of Goods Act. Hence it is repugnant to the State law. Therefore it violates article 254 of the Constitution.

The definition of "works contract" under sub-clause (v-i) of section 2(1) is wider and ultra vires of the definition of "sale" under the Amendment Act No. 27 of 1985.

Section 5B, the charging section on works contract, is ultra vires of section 5(4) of the Act because of the non obstante clause. As a result, the said section contradicts section 5(4) of the Act. In levying the tax, it is arbitrary and without any nexus.

The Rules are ambiguous and contradictory to various clauses provided in it. The nature of the civil contract is such that it is highly impossible to determine and calculate as any other transfer of property in goods the actual quantum of the works carried over every month and to maintain stock books. Clauses (m) and (n) of rule 6, while granting exemption have imposed unreasonable restrictions which are violative of article 19(1)(g) of the Constitution.

The Rules have unnecessarily classified a section scheme of tax structure, one for as