The FAR at 1.602.2 explains how a CO appoints a COR and 1.604 states the COR will follow the letter of designation. But I cannot find any regulations pertaining to the termination or revocation of a COR's designation.
My Executive Agency follows the FAR and has an internal directive that states: "a CO may revoke a CORs designation at any time."
The problem is the Program Office is arguing it cannot be unilateral.