Notwithstanding any other provision in this part, a DOE employee may not authorize or approve, require another person to authorize or approve, or advocate the authorization or approval of, payment from DOE funds of travel expenses of a person who is not a Government employee and who is (a) the DOE employee's relative (except in the case of payment under §1060.101(a)(4)), or (b) in the case of payment under §1060.101(a)(1), a DOE contractor or a DOE assistance award recipient or the employee of a DOE contractor or a DOE assistance award recipient unless the travel expenses are incurred with respect to matters outside the scope of the contract or assistance award, as the case may be. (See also §1060.101(e).)