You should earth one end of the cable. whichever end is easiest disconnect and remove from the gland, cut back the plastic outer PVC sheaf exposing the frayed installation. Untangle about a 4mm CSA length, the length is dependant on where you can connect to an earth. Twist it together, a drill is great for this, until you have what is a condutor. Cut the rest of the frayed protection off. Try and slide a little of the outer PVC insulation back over your "conductor" and wrap a small amount of Yellow'Green tape to stop the PVC slipping.
Back into the gland, sleeve with Yellow/green and terminate into the earth, and all this is of course you have slack