A petition requesting action under this part for the purpose of adjusting to the obligations of the United States under the Agreement may be filed with the Commission by an entity, including a trade association, firm, certified or recognized union, or group of workers, that is representative of an industry. The Commission shall transmit a copy of any petition filed under this subsection to the United States Trade Representative.

Upon the filing of a petition under subsection (a), the Commission, unless subsection (d) applies, shall promptly initiate an investigation to determine whether, as a result of the reduction or elimination of a duty provided for under the Agreement, a CAFTA–DR article is being imported into the United States in such increased quantities, in absolute terms or relative to domestic production, and under such conditions that imports of the CAFTA–DR article constitute a substantial cause of serious injury or threat thereof to the domestic industry producing an article that is like, or directly competitive with, the imported article.

No investigation may be initiated under this section with respect to any CAFTA–DR article if, after the date that the Agreement enters into force, import relief has been provided with respect to that CAFTA–DR article under this part.