RAJU J.

This batch of writ petitions involves for consideration a challenge to Circular No. 681 dated March 8, 1994, issued by the Central Board of Direct Taxes, New Delhi. The impugned circular order is in the form of instructions and guidelines in regard to the applicability of the provisions of section 194C of the Income-tax Act, 1961 (hereinafter referred to as "the Act"), concerning deduction of income-tax at source in relation to certain categories of payments by specified classes of persons or institutions. The impugned circular further purports to withdraw the Board's Circular No. 86 (see [1972] 84 ITR(St) 99) dated May 29, 1972, Circular No. 93 (see [1972] 86 ITR(St) 30), dated September 26, 1972, and paragraph 11 of Circular No. 108 dated March 20, 1973, and reiterates the Board Circular No. 558 (see [1990] 183 ITR(St) 158), dated March 28, 1990 The challenge is made to the impugned circular by different classes of persons. Apart from an advocate who in his individual capacity, has challenged the same (Writ Petition No. 7807 of 1994), professional associations concerning the legal fraternity, the Madras Bar Association (Writ Petition No. 7803 of 1994) and the Madras High Court Advocates Association (Writ Petition No. 7804 of 1994) have also challenged this impugned circular for the benefit of their member-advocates. The Chartered Accountants Study Circle, a society registered under the Tamilnadu Societies Registration Act, 1975, has chosen to file a writ petition challenging the very circular in order to protect the interests of its members, namely, chartered accountants, in Writ Petition No. 8483 of 1994. The Advertising Club, Madras, which also is a society, registered under the Societies Registration Act, has challenged the circular, for and on behalf of its member constituents who are stated to be advertising agencies rendering professional and creative services to their clients, in Writ Petition No. 12406 of 1994. The Madras Goods Transporters' Association, another society registered under the Societies Registration Act has also challenged the circular in question, for and on behalf of its constituent members comprising various firms and companies who are stated to be engaged in transporting goods from Madras to various places by using their own trucks or vehicles as also engaging the trucks and vehicles belonging to other owners, in Writ Petition No. 9020 of 1994. The other writ petitions belong to one or more of the above categories. As a matter of fact, leading submissions have been made in the above noticed writ petitions and the other learned counsel appearing in the remaining writ petitions have adopted the arguments made in those casesBefore adverting to the grounds of challenge, it would be appropriate as also necessary to refer to the salient features of the impugned circular and the earlier circulars withdrawn by the impugned circular. The Finance Act, 1972, has introduced a new section 194C in the Income-tax Act, 1961, with a view to providing for deduction of income-tax at source from income comprised in payments made to contractors and subcontractors in certain cases. Sub-section (1) of section 194C lays down that any person responsible for paying any sum to any resident contractor for carrying out any work or supplying labour for carrying out any work inclusive of a sub-contract in pursuance of a contract with the Central Government, State Government, local authority, statutory corporation or a company, is obliged, at the time of credit of the sum to the account of the contractor or at the time of payment thereof in cash or by issue of a cheque or draft or by any other mode, to deduct an amount equal to two per cent. of such sum as income-tax on the income comprised therein. Likewise, an obligation is cast on the contractor making payment to a resident sub-contractor in pursuance of any contract made with him for carrying out the whole or a part of work undertaken by the contractor or fo