No Federal funds, including any funds in the Postal Service Fund, may be obligated or expended for the purchase of delivery vehicles unless the Postal Service issues a change order on the contract with Oshkosh Defense that requires Oshkosh Defense to—
(1)
agree that its execution of and compliance with a bona fide union neutrality agreement is material to the Government’s payment decisions for purposes of section 3729(b)(4) of title 31, United States Code; and
(2)
certify that it will execute and comply with a bona fide union neutrality agreement covering all production employees within the scope of the contract.