Government contract deposits and amounts due to contractors are protected from attachment, except for employee claims. Any amount deposited with the appropriate Government by an employer to secure due performance of a contract and any other amount due to such employer from that Government in respect of such contract shall not be liable to attachment under any decree or order of any court in respect of any debt or liability incurred by the employer, other than any debt or liability incurred by the employer towards any employee employed in connection with the contract aforesaid.