Any DOT employee shall temporarily disqualify himself or herself from participation in any matter before DOT if he or she represented, was associated with or was employed by an interested person or entity including other agencies of the United States Government before joining DOT, and, although he or she did not personally and substantially participate in the matter, the matter was within his or her “official responsibility,” as that term is defined in § 300.14 of this chapter except that the action referred to therein shall be private action as well as “Government” action. Such disqualification shall be applicable also if a person closely related to the DOT employee as partner, associate, employer, or the like, who, while not personally and substantially participating in the matter, had it within his or her “official responsibility” as that term is defined in § 300.14 of this chapter, and modified above, and the circumstances are such that the DOT employee's subsequent participation in the matter as a DOT employee could fairly be said to create the appearance that his or her participation would be affected by his or her prior relationship. Notwithstanding the foregoing, the disqualification of any DOT employee whose prior “official responsibility” or relationship to one with such responsibility occurred on behalf of another agency of the United States Government shall only be applicable with respect to issues on which the prior governmental employer took a position in the proceeding. The temporary disqualification shall run for a period of one year from the date of the termination of the representation, association, or employment with the interested person or entity.