structure 3 is fed via a hydraulic control line 10 from the pod 8 electrical or optical signals from the scm 2 operate dcvs in the pod 8 which in turn control the hydraulic power from a local source designated u2018 lp low pressure supply u2019 in fig3 to each valve 4 via hydraulic feeds 10 internal to the manifold structure 3 thus the cost of steel hydraulic tubing from the scm to the manifold structure is obviated as is the need to add additional dcvs to the scm fig4 illustrates a second embodiment of the invention relating to the control of downhole valves in this embodiment a pod can be located on the tree but external to the scm thus avoiding the need to modify or expand a minimal standard scm an scm 2 is housed on tree 1 and is connected either electrically or optically via cable 9 to the pod 8 in this embodiment the pod 8 is also mounted on the tree 1 the pod 8 feeds downhole valves 4 via respective hydraulic control lines 7 electrical or optical signals from the scm 2 operate dcvs in the pod 8 which in turn control the hydraulic power from the scm designated u2018 hp high pressure supply u2019 in fig4 to each valve 4 via the hydraulic control lines 7 thus the need to add additional dcvs to the scm is obviated as an alternative form of this embodiment.