New clutch master cylinder is required.
Approx £80 from Ford, comes as an entire pedal assembly.
A friend had one changed on his car. Check the plunger from the pedal into the master cylinder isn't damp, if it is then a new one is required.
Total cost from Ford was <£200, fortunately his was under warranty still.
i'm getting the same problem you press clutch down change gear release pedal and only returns slightly have to put toe under and push up. the clutch not slipping and it drives away its only ocaisionaly happens. think im going change car soon.