Any contract for loan or grant, or both, pursuant to this subchapter shall contain a provision requiring that not less than the wages prevailing in the locality, as predetermined by the Secretary of Labor pursuant to sections
3141–3144,
3146, and
3147 of title
40, shall be paid to all laborers and mechanics employed in the construction of the project at the site thereof; and the Secretary of Housing and Urban Development shall require certification as to compliance with the provisions of this subsection prior to making any payment under such contract.