Well I had a look on Sunday and one caliper is definately not holding with the hand brake, yet the other side is.
I tested this by lifting the car off the ground and tightening the lug nuts with the spanner, the wheel on the passenger's side would turn when i tightened up the nut with the handbrake up but the drivers side wouldnt.
I did notice a different design in rear calipers from the Passenger side to the Drivers side, which makes me think that the drivers side may be a late mk3 caliper. I will try and take some pics next weekend
I sprayed WD40 and tried loosening it up but no joy. Will probably upgrade the caliper now.
Thanks all for your interest and help.