A laterally adjustable rail clip fastening means is provided by the present invention for securing a resilient rail clip such as a Pandrol clip to a direct fixation rail mounting assembly, and, in turn, into engagement with a rail. The rail clip fastening means includes a pair of sections formed of rigid material having a curved section at one end to receive and securely hold a resilient rail clip in engagement with a rail. The sections of rigid material are laterally moveable along the top plate of the rail mounting assembly and include cam locking means to independently lock such sections into position against the rail for preventing lateral movement thereof in cooperation with the resilient rail clips.