“Contractor”, in relation to an establishment, means the one who supplies contract labour to an establishment undertaking to produce a given result for it other than a mere supply of goods or articles of manufacture to such establishment. He hires labour in connection with the work of an establishment and includes a sub-contractor.

“Principal Employer” means-

  (i) in relation to any office or department of the Government or a local authority, the    head of that office or department or such other officer as “‘the Government or the local authority, as the case may be, may specify in this behalf,

(ii) in a factory, the owner or occupier of the factory and where a person has been named as the manager of the factory under the Factories Act, 1948 (63 of 1948), the person so named.

The act applies to every contractor who employs or who employed twenty or more workmen on any day of the preceding twelve months as per Section. 1(4)(b) of the act

The applicability of the act to Principal Employer can be seen only in reference to an establishment in place under Sec. 1(4)(a). The act applies to every establishment in which twenty or more workmen, are employed or were employed on any day of the preceding twelve months as contract labour.