A mechanism for driving a first member for adjusting the orientation of the blades of a first stage of a turbine engine diffuser and a second member for adjusting the orientation of the blades of a second stage of the turbine engine diffuser, including a single drive wheel which simultaneously drives the first adjustment member and the second adjustment member and a set of gears which is arranged between the drive wheel and the two adjustment members, wherein the set of gears includes a first gearwheel which is directly coupled with the drive wheel and with the first adjustment member and which is coupled with the second adjustment member with a secondary gearwheel which is directly coupled with the second adjustment member.