If its not a twin and earth in the board and arrives as singles make sure you no' them up as he will pull you on this.Cheers. The earth for the circuit would come with the live to the switch (3gang) then off from there to each of the lights, again as a pvc/pvc single and earth. Then each of the lights connected together with a pvc/pvc single neutral going back to cu.
So definately no need to have an earth with this neutral cable as well?? I just felt the poor fella might be a bit lonely and the NICEIC inspection bloke might question why he hasn't got a little buddy coming along for the ride?