All laborers and mechanics employed by contractors or subcontractors on projects assisted by the Secretary 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 subchapter IV of chapter 31 of title 40. The Secretary shall not extend any financial assistance under this chapter for such a project without first obtaining adequate assurance that these labor standards will be maintained upon the construction work. The Secretary of Labor shall have, with respect to the labor standards specified in this provision, the authority and functions set forth in Reorganization Plan Numbered 14 of 1950 (15 F.R. 3176; 64 Stat. 1267), and section 3145 of title 40.