All laborers and mechanics employed by contractors or subcontractors in the construction, alteration or repair, including painting and decorating of projects, buildings and works which are federally assisted under this chapter shall be paid wages at rates not less than those prevailing on similar construction in the locality as determined by the Secretary of Labor in accordance with sections 3141-3144, 3146, and 3147 of title 40. The Secretary of Labor shall have, with respect to such labor standards, the authority and functions set forth in Reorganization Plan Number 14 of 1950 (15 F.R. 3176; 64 Stat. 1267) and in section 3145 of title 40.