20. LIABILITY OF PRINCIPAL EMPLOYER IN CERTAIN CASES. –
(1) If any amenity required to be provided under section 16, section 17, section 18 or section 19 for the benefit of the contract labour employed in an establishment is not provided by the contractor within the time prescribed therefor, such amenity shall be provided by the principal employer within such time as may be prescribed.
(2) All expenses incurred by the principal employer in providing the amenity may be recovered by the principal employer from the contractor either by deduction from any amount payable to the contractor under any contract or as a debt by the contractor.
Obligation to provide amenities conferred by the Act to the workers is on the principal employer; People’s Union for Democratic Rights v. Union of India, 1982 (3) SCC 235.