; and (2) not, during the performance of the contract, initiate, carry out, or enforce any system of quotas, benchmarks, or goals in regard to employment practices which encourage or require any discrimination on the basis of race. (b) Exception for lookback requirement Notwithstanding subsection (a), the Secretary may exempt the head of an executive agency from the requirement to include the certification described in subsection (a)(1) in a specific contract, subcontract, or purchase order if the Secretary determines that special circumstances in the national interest so require. 5. Regulations and implementation (a) Regulations required (1) Department of labor Not later than 90 days after the date of enactment of this Act, the Secretary shall issue such regulations as are necessary to implement this Act. (2) Federal acquisition regulation Not later than 90 days after the date on which the Secretary issues regulations under paragraph (1), the Federal Acquisition Regulatory Council shall amend the Federal Acquisition Regulation, consistent with such regulations, to provide for inclusion in any Federal procurement solicitation or contract the requirements under section 4. (b) Agency implementation Not later than 90 days after the date on which the Secretary issues any regulations under subsection (a)(1) and except as provided in section 4(b), the head of each executive agency shall ensure that any contract entered into by the executive agency complies with the requirements set forth in section 4(a). 6. Enforcement (a) In general The Secretary shall have the authority to investigate potential violations of this Act and obtain compliance, including as provided in subsection (b). (b) Penalties for noncompliance In the case of a contractor that violates a contract requirement under section 4— (1) the relevant executive agency may cancel, terminate, or suspend (in whole or in part) the applicable contract; and (2) the Secretary may initiate a debarment proceeding with respect to the contractor.