I tried 2 different fuses, just to be sure. But the old one was okay.

I checked all the filiments in the bulbs, they seem to be okay. I changed them to be sure.

I check the ground wires on the left and right brake lights and they seem to be okay.

I looked in my Haynes manual and these appear to be on the same ciruit. The blinkers and parking lights work (different circuit.)

I recently had the Slave Cylinder for the Clutch repaired cause it was leaking. Is it possible that the technicain that fixed it may have accidently messed with something along the curcuits path?

I could only think it be a ground issue somewhere. Not really sure where to start hunting for it though.

Anyone got any clues?

check the brake pedal switch.