(a) A petition under section 406(a) of the Trade Act may be filed by an entity, including a trade association, firm, certified or recognized union, or group of workers, that is representative of a domestic industry producing an article with respect to which there are imports of a like or directly competitive article which is the product of a Communist country, which imports, allegedly, are increasing rapidly, either absolutely or relative to domestic production, so as to be a significant cause of material injury, or the threat thereof, to such domestic industry.

(b) A petition under section 421(b) or (o) of the Trade Act may be filed by an entity, including a trade association, firm, certified or recognized union, or group of workers, which is representative of an industry.