A method of assembling electric power supply cables on a stator of an electric motor including the following steps: electrically connecting an end of each cable to an end of at least one respective wire of the winding; inserting each pair of connected ends into a respective small tube of a protection and positioning element made of insulating plastic and having a strip from which a number small tubes at least corresponding to the number of electric power supply cables transversally protrudes; clamping each small tube so as to fix it to the pair of ends inserted inside it; inserting an end of the strip inside a cavity of the pack, so that the small tubes are located within the head; and tying the winding in the region of the head so as to enclose the small tubes.