Cable Question changing MR16 to LED GU10's

[mileslt]

Hi I am replacing all my MR16 spotlights with GU10 LED spotlights, origional I was planning just to cut the cable just before the MR16 transformer and 're attach to the new  GU10 spotlights but I noticed the 0.75 cable that goes from the light to the Junction box above is not earthed. Should this be changed for GU10s? As don't have transformers? And if so will i be ok using 3 core 0.75 flex ? Or should I use twin and earth 1.5 cable like what's used above the junction box?